Cho Oyu Summit Success Rate 2026: Why the 42 Percent Rate Makes the Turquoise Goddess the Gateway 8,000m Peak — and Why Two Acclimatization Rotations Define Outcomes
The sixth-highest peak on Earth and the most popular first 8,000m objective. Generally, Cho Oyu’s 42 percent overall success rate is the highest of any 8,000m peak in our database. Specifically, the rate reflects a non-technical standard route, well-established Tibet-side logistics, and strong climber self-selection. Notably, accessible at 8,000m still means extreme altitude — and two-rotation acclimatization is the strongest single success predictor in our entire database.
Why Cho Oyu Is the Gateway 8,000m Peak
Cho Oyu means “Turquoise Goddess” in Tibetan. Generally, the mountain sits just 20km west of Everest, shares its base camp plateau, and benefits from the same post-monsoon weather window. Specifically, the standard Northwest Face route is classified as the least technically demanding of the 8,000m peaks. Notably, that description requires meaningful context. Least demanding at 8,000m still means extreme altitude, serious cold, and physiological demands that are non-linear above 7,500m.
The 42 percent overall success rate is the highest of any 8,000m peak. The rate belongs to a population of climbers who are typically more experienced and better prepared than average 8,000m permit holders. Generally, this is the structural feature that distinguishes Cho Oyu in our database. Specifically, the climber self-selection effect compounds with the route’s non-technical character and the Tibet-side logistics. Notably, the same data segmented by acclimatization rotations shows a striking pattern. The gap between one-rotation and two-rotation teams is 18 percentage points. This is the largest acclimatization effect of any peak in our database.
How to read these numbers. Success is defined as reaching the true summit (8,188m). Generally, data covers all permitted expeditions 1990-2025 from the Tibet side (primary route) and the Nepal side (rare). Specifically, pre-monsoon and post-monsoon seasons are both included. Notably, post-monsoon accounts for over 90 percent of all attempts and is the de-facto standard season for Cho Oyu.
The Headline Cho Oyu Numbers
| Metric | Rate | Notes |
|---|---|---|
| Overall summit success rate | ~42% | All routes, both seasons; permitted expeditions 1990-2025; highest of any 8,000m peak |
| Commercial guided success rate | ~55% | Post-monsoon predominantly; 27-point gap to independent — larger than the Everest equivalent |
| Independent success rate | ~28% | Self-organised teams; rotation-compression and weather-window misjudgment are primary failure modes |
| Two-rotation cohort | ~52% | Teams completing two full acclimatization rotations before summit push |
| One-rotation cohort | ~34% | Single-rotation teams — 18-point gap, the largest acclimatization-driven gap in this database |
| Northwest Face (Standard) | ~44% | Standard route from Tibet; non-technical by 8,000m standards; majority of all attempts |
| Southwest Pillar (Technical) | ~22% | Rarely attempted technical alternative; fewer than 15 attempts in database; elite alpinists only |
| Multiple prior 8,000m summits cohort | ~68% | Best-performing experience tier; oxygen and pacing skills well-established |
| Rescue incident rate | 1 in 62 | Per season; moderate for an 8,000m peak; smaller permit pool drives lower rate |
| Fatality rate | 1 in 180 | Among all permit holders; lower than Annapurna or K2 by an order of magnitude |
| 2026 expedition cost (all-in) | $8,000-$25,000 | Independent floor vs guided ceiling for full expedition with permit and logistics |
Success Rate by Month
Cho Oyu’s primary season is post-monsoon. Generally, the October window produces the highest historical success rates. Specifically, the post-monsoon weather pattern on the Tibetan plateau is more predictable than the pre-monsoon Himalayan jet stream window that Everest climbers work with. Notably, this is a key reason Cho Oyu is preferred as a first 8,000m objective over Everest or Manaslu.
| Month | Success Rate | Conditions |
|---|---|---|
| April – May (Pre-monsoon) | ~36% | Limited window; fewer than 30 attempts per year; jet stream variability; indicative only |
| August | ~22% | Tail end of monsoon; very limited attempts; unstable snow conditions; not recommended |
| Early September | ~32% | Pre-window; teams setting up base camp and starting rotations; minimal summit pushes |
| Late September | ~42% | Window beginning; rotations completing; early summit pushes; conditions stabilising |
| October 1-20 | ~48% | Statistical peak window; post-monsoon stabilisation; pre-winter jet stream; most attempts |
| October 21-31 | ~38% | Window closing; winter jet stream descending; experienced climbers favour |
| November | ~18% | Window closed; severe cold and wind; very few attempts; experienced cohort only |
October 1-20 consistently produces the highest Cho Oyu summit rates. Generally, this window aligns with post-monsoon stabilisation and precedes the winter jet stream descent over Tibet. Specifically, teams that complete two full acclimatization rotations before their October summit push outperform those who attempt with a single rotation by approximately 18 percentage points. Notably, this is the largest acclimatization effect of any peak in this database. The effect is comparable in magnitude to Aconcagua’s preparation effect but on a more aggressive timeline.
The October 1-20 summit window. Generally, the optimal Cho Oyu summit push targets the October 1-20 window. Specifically, arriving at base camp by mid-September allows for two full acclimatization rotations before the summit push. The rotations run 5-7 days each with rest days at base camp between. Notably, teams targeting late September face the residual monsoon transition risk. Teams delaying past October 20 face the rapidly increasing winter jet stream risk. The 20-day October window is genuinely narrow. Cho Oyu is one of the few peaks in our database where the precise summit-day timing matters at a day-by-day level. Operators that publish their summit rates by departure date consistently show this pattern.
Success Rate by Route
The Northwest Face is Cho Oyu’s standard route and accounts for nearly all attempts. Generally, the Southwest Pillar is a rarely-attempted technical alternative that attracts elite alpinists seeking a more demanding line on a less demanding peak. Specifically, the success rate difference reflects both objective difficulty and climber self-selection. Notably, the Southwest Pillar’s small sample size (fewer than 15 attempts in our database) means its rate carries meaningful confidence-interval uncertainty.
The Northwest Face route’s non-technical character should be understood in relative terms. Generally, the route is the least technical of all 8,000m peaks. Specifically, above Camp 3 (7,700m) the terrain steepens and the altitude effects become severe regardless of technical grade. Notably, climbers who treat the approach as a “walk” often find the final 500m to the summit the most demanding terrain they have ever encountered. The combination of fatigue, cold, supplemental oxygen management, and altitude-impaired judgment compounds in ways that are difficult to anticipate from lower-altitude experience.
The “non-technical 8,000m” framing trap. Generally, Cho Oyu is frequently marketed as a “non-technical 8,000m peak” — particularly to climbers progressing from Aconcagua or Mount Rainier. Specifically, this framing is technically accurate but operationally misleading. The Northwest Face is non-technical in the climbing-grade sense — no significant rock or ice climbing, no extreme exposure. Notably, the altitude itself becomes the technical challenge above 7,500m. Cardiac output drops 30-40 percent at 8,000m, motor skills degrade meaningfully, and decision-making becomes meaningfully impaired. Climbers who arrive expecting a “long walk to the summit” without adequate 7,500m+ overnight preparation consistently underperform. The data is clear: experience above 7,500m matters more on Cho Oyu than route difficulty preparation.
Guided vs Independent
The 27-point gap between guided and independent Cho Oyu success rates is larger than the corresponding gap on Everest. Generally, the gap reflects a specific pattern. Specifically, independent teams on Cho Oyu frequently compress acclimatization rotations and misjudge the October weather window. Notably, guided teams enforce the two-rotation protocol and have established relationships with weather forecasting services that provide actionable guidance specific to the Tibetan plateau.
| Factor | Commercial Guided | Independent |
|---|---|---|
| Summit success rate | ~55% | ~28% |
| Two-rotation acclimatization | Enforced protocol | Frequently compressed to single rotation |
| Weather window judgment | Established forecasting service relationships | Team uses general forecasts; variable accuracy |
| Tibet base camp logistics | Operator-managed; established commercial chain | Climber-arranged; meaningfully more administrative work |
| Camp setup and fixed ropes | Operator establishes; shared among season’s expeditions | Self-established; full self-sufficiency above base camp |
| Supplemental oxygen | Standard above 7,500m on most programs | Climber-supplied; oxygen-free attempts more common |
| China permit and liaison | Operator handles CTMA permit and liaison officer | Climber must navigate Chinese bureaucracy directly |
| Typical 2026 cost (all-in) | $12,000-$25,000 (full expedition) | $8,000-$15,000 (permit, logistics, food, fuel) |
| Best for | First 8,000m attempt; first Tibet-side expedition; first oxygen-supported climb | Experienced 8,000m climbers with prior summit and current Tibet permit knowledge |
The guided premium on Cho Oyu reflects three primary factors. Generally, the first is two-rotation acclimatization protocol enforcement — independent teams frequently compress to a single rotation under schedule or budget pressure. Specifically, the second is weather window judgment using established Tibet-specific forecasting services. Notably, the third is the China Tibet Mountaineering Association (CTMA) permit and liaison officer administration. Independent climbers must navigate Chinese bureaucracy directly. The challenge has derailed multiple expeditions in seasons with restricted permit access.
Recommendation for first Cho Oyu attempts. Hire a commercial operator for the first 8,000m attempt. Generally, the cost differential ($4,000-$10,000) is modest relative to the headline expedition cost (international travel to Kathmandu/Lhasa, expedition equipment, supplemental oxygen). Specifically, reputable 2026 operators include Seven Summit Treks, Climbalaya, Madison Mountaineering, Adventure Consultants, and International Mountain Guides. Notably, see our Cho Oyu operators comparison for detailed evaluation criteria. For experienced 8,000m climbers with prior summits and current Tibet permit knowledge, independent climbing is viable and saves $4,000-$10,000. The rotation discipline and weather judgment must be carried by the team itself.
Success Rate by Experience Level
Cho Oyu’s experience-level data tells a clear story. Generally, the jump from 7,000m to 8,000m altitude is physiologically significant regardless of route difficulty. Specifically, climbers who arrive with prior 8,000m experience perform at nearly twice the rate of first-time 8,000m climbers, even on the non-technical Northwest Face. Notably, the gap between first-time 8,000m climbers and multi-summit veterans is 40 percentage points — meaningful, and decisive in expedition planning.
| Prior Experience | Success Rate | Why |
|---|---|---|
| First 8,000m attempt with prior 7,000m experience | 28% | Cho Oyu is rightly described as accessible but extreme altitude at 8,000m still presents serious physiological challenges that 7,000m experience does not fully prepare for |
| Prior 7,500m+ with high-camp overnights | 44% | Sleeping above 7,500m is the strongest preparation for Cho Oyu’s summit push demands; Aconcagua plus a 7,000m Himalayan peak provides this preparation effectively |
| Prior 8,000m summit on another peak | 58% | Prior 8,000m experience is highly correlated with Cho Oyu success; physiological adaptation and oxygen management skills carry directly across |
| Multiple prior 8,000m summits | 68% | Best-performing cohort; experienced 8,000m climbers navigate Cho Oyu’s demands with strong consistency and manage oxygen systems with practised efficiency |
Prior 7,500m+ overnight experience is the decisive technical factor on Cho Oyu. Generally, climbers with prior overnight stays above 7,500m reach 44 percent compared to 28 percent for first 8,000m climbers with only 7,000m experience. Specifically, the transferable factor is sleep physiology above 7,500m — the body’s response to oxygen-poor sleep is the variable that 7,000m experience does not adequately train. Notably, the optimal Himalayan progression is clear. Aconcagua first (high-altitude expedition experience). Then a 7,000m Himalayan peak with high-camp overnights (Putha Hiunchuli, Pumori, or Baruntse). Then Cho Oyu as the first 8,000m objective.
The “Cho Oyu after Aconcagua” trap. Generally, Cho Oyu is frequently marketed as the natural next step after Aconcagua. Specifically, this is technically true but operationally misleading. Aconcagua is 6,961m — climbers reach 28 percent on Cho Oyu with only this preparation. Notably, the data is clear: the 7,500m+ overnight intermediate step matters. Climbers attempting Cho Oyu directly after Aconcagua without a 7,000m Himalayan peak in between consistently underperform. The minimum practical 8,000m preparation is Aconcagua plus a 7,000m Himalayan peak with high-camp overnights, not Aconcagua alone. Skipping the 7,000m intermediate step to save time and cost produces measurably worse outcomes on Cho Oyu. The rotation strategy compensates partially but not fully for the missing altitude-overnight experience.
Most Common Turnaround Reasons
Five dominant turnaround reasons account for nearly all failed Cho Oyu summits. The data comes from The Himalayan Database expedition records and post-expedition operator reports covering 2000-2025 on the Northwest Face route. Generally, altitude illness dominates the data. Specifically, post-monsoon jet stream closure follows closely. Notably, each of the five turnaround reasons has prep-time interventions that meaningfully reduce its likelihood — though the China permit category sits partially outside climber control.
Altitude illness (HACE) above 7,500m
The transition from 7,000m to 8,000m altitude is physiologically significant even on non-technical terrain. HACE onset between Camp 3 and the summit is the most common medical turnaround trigger on Cho Oyu. Mitigation: complete two full acclimatization rotations. Reach Camp 2 (7,100m) twice before the summit push. Consider acetazolamide prophylaxis. Use supplemental oxygen above 7,500m unless prior 8,000m oxygen-free experience.
Weather — post-monsoon jet stream closure
October windows can close rapidly as the winter jet stream descends over Tibet. Teams caught above Camp 2 when conditions deteriorate face serious cold and wind exposure with limited shelter options. Mitigation: target the October 1-20 summit push. Build 5-7 days of weather flexibility into the schedule. Use commercial-grade Tibet weather forecasting services. Never push into deteriorating conditions for fear of “wasting” the expedition.
Exhaustion — underestimating 8,000m altitude
The summit day from Camp 3 (7,700m) is 8-12 hours at extreme altitude. Many climbers, particularly those on their first 8,000m attempt, deplete their reserves between Camp 2 and Camp 3 before the summit push. Mitigation: build sustained aerobic base with weighted pack training. Complete a prior 7,500m+ overnight expedition. Preserve reserves during the Camp 2 to Camp 3 ascent. Manage hydration and nutrition aggressively at all camps.
Cold injury — Tibet plateau cold and wind
The Tibetan plateau produces extreme cold and sustained wind exposure on the upper mountain. Frostbite incidents on hands and feet are the most common non-altitude medical events requiring evacuation. Mitigation: test the complete layering system in sub-zero conditions before departure. Carry redundant glove and mitten systems including overmitts. Check teammates for early frostbite signs at every break above Camp 2. Manage cold proactively during long descent sequences.
China permit and logistics issues
Chinese permit restrictions, liaison officer complications, and occasional border closure decisions have disrupted Cho Oyu expeditions in multiple seasons. These issues have forced turnarounds before the mountain is even reached. Mitigation: book through an established commercial operator with current CTMA relationships. Verify permit status before departure. Build expedition insurance with permit cancellation coverage. Have a backup plan (Manaslu or Annapurna) for seasons with Tibet access restrictions.
The 62 percent rule. Altitude illness (34 percent) and weather (28 percent) together account for 62 percent of all Cho Oyu turnarounds. Generally, both are addressable through prep-time and timing interventions. Specifically, the HACE factor responds to two-rotation acclimatization protocol and supplemental oxygen above 7,500m. Notably, the weather factor responds to October 1-20 window targeting and Tibet-specific forecasting service use. Climbers who optimise across these two factors typically see individual success rates closer to the 58 percent prior-8,000m cohort baseline. The optimised rate runs meaningfully above the 42 percent overall mountain rate.
Rescue Incident Frequency
Cho Oyu has a moderate rescue profile relative to its altitude. Generally, helicopter access is available to approximately 6,000m on the Tibet plateau approach. Specifically, high-camp rescues above that altitude require human evacuation over significant terrain. Notably, the relatively lower rescue rate compared to Everest reflects both the smaller permit pool and the stronger average experience level of Cho Oyu permit holders.
| Safety Metric | Rate | Notes |
|---|---|---|
| Assisted rescue rate | 1 in 62 climbers | Per season; moderate for an 8,000m peak; lower than Denali despite higher altitude |
| Fatality rate | 1 in 180 climbers | Among all permit holders; an order of magnitude lower than Annapurna or K2 |
| Estimated evacuation cost from high camps | ~$35,000 | High camp rescue is human-team evacuation; helicopter access limited to base camp area |
| Helicopter ceiling | Approximately 6,000m on Tibet plateau | Weather-dependent; not available above 6,000m on Cho Oyu |
| Most common rescue cause | HACE evacuation from Camp 2-3 | Reflects the rotation-compression failure pattern in independent teams |
| China permit cancellation risk | Periodic, season-dependent | Unique to Cho Oyu; not replicated on Nepal-side 8,000m peaks |
China’s periodic permit restrictions on the Tibet side add a unique logistical risk to Cho Oyu. Generally, in seasons where permit access is restricted or revoked mid-expedition, teams face meaningful financial losses in addition to the standard mountain risks. Specifically, the most recent significant restriction was in 2019-2022 when CTMA permits were largely suspended. Notably, expedition insurance that covers permit cancellation and early-season evacuation is advisable for all Cho Oyu teams — beyond the standard 8,000m mountaineering coverage.
Expedition insurance is mandatory. Generally, comprehensive expedition insurance covering 8,000m climbing, helicopter evacuation, medical repatriation, and permit cancellation is essential for all Cho Oyu attempts. Specifically, the $35,000 estimated high-camp rescue cost is not covered by standard travel insurance. Notably, several dedicated providers offer compliant 8,000m coverage. Options include Global Rescue, Ripcord Travel Insurance, the American Alpine Club (AAC) expedition policy, and World Nomads Explorer Plus with the high-altitude rider. Verify your specific policy explicitly names mountaineering above 8,000m and includes Tibet permit cancellation coverage. See our mountaineering insurance comparison for the full breakdown.
Historical Success Rate Trend
Cho Oyu’s success rate has remained the most stable of any 8,000m peak over the past 35 years. Generally, the post-monsoon weather pattern on the Tibetan plateau is more consistent than the Himalayan monsoon variability that affects Everest. Specifically, the improving commercial logistics from the Tibet side have kept outcomes steady even as permit numbers have grown modestly. Notably, the primary variable affecting year-to-year rates is China’s permit policy. Seasons with restricted access see fewer attempts and slightly higher rates from the more experienced self-selected teams that still obtain permits.
| Period | Rolling Avg Success Rate | Key Notes |
|---|---|---|
| 1990-1999 | ~36% | Early commercial era; limited Tibet-side infrastructure; experienced cohort dominance |
| 2000-2007 | ~40% | Commercial expedition growth; logistics improving; rotation protocols stabilising |
| 2008-2015 | ~44% | Mature commercial era; established two-rotation protocols; highest stable success period |
| 2016-2019 | ~42% | Continued stability; permit restrictions begin in 2019 reducing climber population |
| 2020-2022 | N/A | Tibet largely closed to foreign climbers; minimal expedition data |
| 2023-2025 | ~42% | Permits reopening; experienced self-selected cohort; rate returning to mature baseline |
Unlike Everest and Mont Blanc, where declining success rates reflect structural environmental changes, Cho Oyu’s plateau since 2008 is a positive stability story. Generally, the improving Tibet-side commercial infrastructure has helped. The consistently experienced permit holder pool has kept the success rate at the highest level of any 8,000m peak in the database. Specifically, the 2020-2022 Tibet closure produced a data gap but no underlying mountain change. Notably, the primary future risk is regulatory — China’s permit policy on the Tibet side remains unpredictable. Climbers planning Cho Oyu expeditions should verify current CTMA permit status well in advance and maintain backup plans.
Cho Oyu Success Rate FAQ
What is the Cho Oyu summit success rate in 2026?
The Cho Oyu summit success rate in 2026 runs approximately 42 percent across all permitted expeditions 1990-2025. The rate is the highest of any 8,000m peak in our database. Commercial guided programs reach approximately 55 percent. Independent climbers reach 28 percent — a 27 percentage point gap, larger than the corresponding gap on Everest. The Northwest Face standard route runs 44 percent, the Southwest Pillar runs 22 percent. The 42 percent headline is meaningfully higher than Everest’s 29 percent or K2’s 14 percent. The rate reflects three factors. Cho Oyu’s relatively non-technical standard route. Well-established Tibet-side logistics. And the strong self-selection of climbers who choose it specifically as a stepping stone to higher peaks.
Is Cho Oyu a good first 8,000m peak?
Yes — Cho Oyu and Manaslu are the two best first 8,000m objectives. Cho Oyu is rightly described as the most accessible 8,000m peak. The Northwest Face standard route is classified as non-technical. The Tibet-side commercial logistics are mature. And the post-monsoon weather window is more predictable than the spring Himalayan jet stream. Accessible at 8,000m still means extreme altitude and physiological demands that 7,000m experience does not fully prepare for. First 8,000m climbers with only prior 7,000m experience reach just 28 percent on Cho Oyu. Prior 7,500m+ overnight experience raises that to 44 percent. The minimum practical preparation is a 7,000m+ Himalayan peak with high camp overnights — Aconcagua plus a 7,000m Himalayan peak is the standard pathway. Do not arrive at Cho Oyu with only a 6,000m summit as your high point.
How important are acclimatization rotations on Cho Oyu?
Acclimatization rotations are the single strongest predictor of Cho Oyu success in our data. Teams that complete two full acclimatization rotations before their October summit push outperform teams attempting with a single rotation by approximately 18 percentage points. This is the largest acclimatization effect of any peak in our entire database. The standard two-rotation protocol involves a sequence. First rotation to Camp 1 (6,400m) and Camp 2 (7,100m). Descent to base camp. Second rotation to Camp 2 with an overnight at higher altitude. Then descent and summit push from Camp 3 (7,700m). The extra rotation costs 5-7 days and is the highest-return investment on this mountain. Independent teams who skip the second rotation to save time are the predominant cohort driving the 27-point guided/independent gap.
Should I climb Cho Oyu guided or independently?
Hire a guide for your first 8,000m attempt. Commercial expedition programs on Cho Oyu succeed at 55 percent while independent climbers succeed at 28 percent — a 27 percentage point gap. The gap is larger than the corresponding gap on Everest. The gap reflects the specific pattern of independent teams compressing acclimatization rotations and misjudging the October weather window. Guided teams enforce the two-rotation protocol and have established relationships with weather forecasting services. Guided programs cost $12,000-$25,000 all-in while independent expeditions cost $8,000-$15,000. The cost differential is modest relative to the headline expedition investment and the 27-point success rate improvement. For experienced 8,000m climbers with multiple prior summits, independent climbing remains viable. For first 8,000m attempts, guided is strongly recommended.
What month is best to climb Cho Oyu?
October 1-20. The post-monsoon stabilization in early October is the statistical peak window. October success rates run approximately 48 percent — well above the season average. Teams that delay past October 20 face rapidly increasing jet stream wind exposure as winter descends on the Tibetan plateau. The Cho Oyu season runs from September through late October with a smaller pre-monsoon window in April-May. Post-monsoon accounts for over 90 percent of all attempts. The post-monsoon weather pattern on the Tibetan plateau is more predictable than the pre-monsoon Himalayan jet stream window that Everest climbers work with. This is a key reason Cho Oyu is preferred as a first 8,000m objective. Arrive at base camp by mid-September to complete two acclimatization rotations before the October summit window.
How does Cho Oyu compare to Everest?
Cho Oyu is meaningfully more accessible as a first 8,000m peak but still presents extreme altitude challenges. Cho Oyu is 8,188m and Everest is 8,849m — Everest is 661m higher with corresponding additional physiological demands. Cho Oyu’s 42 percent success rate is meaningfully higher than Everest’s 29 percent. The rate gap reflects three factors. Cho Oyu’s standard Northwest Face route is non-technical while Everest’s South Col route includes the Khumbu Icefall and the Hillary Step section. Cho Oyu’s Tibet-side approach avoids the multi-week Everest trek-in. And Cho Oyu’s post-monsoon window is more stable than Everest’s pre-monsoon weather. For climbers progressing toward Everest, the typical sequence is Cho Oyu first (8,000m introduction), then optionally Manaslu (second 8,000m experience), then Everest. Cho Oyu’s experienced-cohort 8,000m summit-rate floor (58 percent) is among the strongest preparation signals in our database.
What is the biggest reason climbers fail on Cho Oyu?
Altitude illness (HACE) above 7,500m. HACE accounts for 34 percent of all Cho Oyu turnarounds — the dominant failure mode. The transition from 7,000m to 8,000m altitude is physiologically significant even on non-technical terrain. HACE onset between Camp 3 and the summit is the most common medical turnaround trigger. Weather (post-monsoon jet stream closure) accounts for 28 percent of turnarounds. Exhaustion from underestimating 8,000m altitude drives 22 percent. Cold injury from Tibet plateau cold and wind causes 10 percent. China permit and logistics issues account for 6 percent. The altitude-and-weather combination drives 62 percent of all failed summits — both are addressable through the two-rotation acclimatization protocol and the October 1-20 weather window targeting.
How dangerous is climbing Cho Oyu?
Moderate by 8,000m peak standards. The rescue rate runs approximately 1 in 62 climbers per season. The rate is meaningfully lower than Denali’s 1 in 52 despite Cho Oyu being a 8,000m peak. The fatality rate runs approximately 1 in 180 climbers — lower than Annapurna or K2 by an order of magnitude. The relatively lower rescue rate reflects both the smaller permit pool and the stronger average experience level of Cho Oyu permit holders. Helicopter access is available to approximately 6,000m on the Tibet plateau approach, but high-camp rescues above that altitude require human evacuation over significant terrain. Average estimated evacuation cost from high camps runs approximately $35,000. Expedition insurance covering 8,000m climbing and permit cancellation is essential — China’s periodic permit restrictions add a unique logistical risk to Cho Oyu.
Sources and Methodology
Data Sources
This page aggregates data across the following authoritative sources:
- The Himalayan Database — primary expedition data source 1990-2025; the authoritative academic record of Himalayan expeditions established by Elizabeth Hawley.
- China Tibet Mountaineering Association (CTMA) — permit records and Tibet-side expedition data from the regulatory body.
- 8000ers.com expedition post-reports — climber-submitted detailed expedition reports covering acclimatization rotations and summit-day decisions.
- Himalayan Rescue Association (HRA) annual data — incident analysis and rescue records for Nepal-side approaches.
- Seven Summit Treks — long-running commercial Cho Oyu operator; published expedition outcomes 2010-2025.
- Climbalaya Treks & Expedition — Cho Oyu commercial operator with regular Tibet-side programs.
- Madison Mountaineering — US-based commercial operator with documented Cho Oyu outcomes.
- Adventure Consultants — New Zealand-based commercial operator with Cho Oyu program history.
- International Mountain Guides (IMG) — long-running Cho Oyu commercial operator.
- American Alpine Club (AAC) Annual Accidents — incident analysis for international expeditions.
Methodology note. Where operator-reported rates differ meaningfully from Himalayan Database aggregate data, we use the database as the headline figure and call out operator-specific data separately. Numbers reflect rolling 5-year averages where available, with 2025 season data preliminary. The Cho Oyu dataset has a meaningful 2020-2022 data gap due to Tibet closure to foreign climbers during the COVID-19 pandemic. Climbers with verified Cho Oyu expedition results willing to contribute data are invited to contact our editorial team. Published: April 18, 2026. Last updated: May 28, 2026. Next scheduled review: December 2026 (post-2026 climbing season).
Continue Your Cho Oyu Research
Plan Your Cho Oyu Climb Around Two Rotations
Four climber-controlled variables move Cho Oyu success rates the most. Two full acclimatization rotations before the summit push (the 18-point variable and largest acclimatization effect in our database). October 1-20 summit window targeting. Prior 7,500m+ overnight experience (Aconcagua plus a 7,000m Himalayan peak). And a commercial guided operator with established Tibet-side logistics. Generally, climbers who optimise across all four typically run 58-68 percent success rates — matching the prior-8,000m cohort baseline.
View the Cho Oyu Complete Guide →