Best Mountain to Climb Each Month of the Year

May is widely considered the best month to climb Mount Everest. Per Dale Remsberg, technical director of the American Mountain Guides Association (AMGA), May is “the time of the year when you have the highest chance of getting to the summit.” The May window has four convergent advantages: minimal rainfall, low prevailing winds (the jet stream lifts off the summit by early May), good visibility, and warmer temperatures than April or earlier. Most commercial Everest summits occur between May 15 and May 30, with operator-specific weather windows clustering in this period. September-October autumn climbing is technically possible but substantially less common — most operators run only spring expeditions. Winter Everest (December-February) is among the most dangerous pursuits in mountaineering — temperatures near -40°C, hurricane-force winds exceeding 100 mph, and the jet stream sitting directly atop the mountain. Summer Everest (June-August monsoon) is universally avoided due to heavy rainfall, avalanche risk, and obscured visibility.

Per Ian Taylor Trekking’s 2026 analysis — yes, often. Ian Taylor has summited Aconcagua more than 11 times, with 7 of those 11 summits occurring in February. His published reasoning: “December and January can still be excellent months for climbing Aconcagua. However, we strongly recommend choosing dates when there are fewer people on the mountain. Having climbed Aconcagua more than 11 times, I personally prefer February, when conditions can still be very good but the crowds are often significantly reduced… I have stood on the summit in February wearing nothing more than liner gloves and a fleece layer — a clear reminder that conditions can still be excellent later in the season.” The structural advantage of February is reduced congestion at the technical sections, lower permit fees (mid-season vs. high-season), and weather windows that are statistically comparable to “prime” December-January. The popular framing — “mid-December through mid-January is the best weather window” — is largely a function of when climbers can take time off work for Christmas-New Year vacation periods rather than when conditions are actually optimal. February rewards climbers with schedule flexibility.

June 5–15 is the canonical Denali summit window per Explore7Summits’ published analysis: “While some go in early May, the chances of frostbite and extreme cold are higher, and most target summit dates from 5–15 June. Going earlier you have better glacier conditions and crevasses are mostly covered and better bridged. Later in the season you gain the warmth, but house sized crevasses, weak snow bridges and the glacial heat can create a truly fearful descent.” The Denali climbing season runs from late April through mid-July, but the optimal window is mid-May through mid-June. Per Atlas & Boots: “Although it’s colder earlier in the season, May and June are considered the best times to climb as they can still offer milder temperatures with fewer crevasses. By late July, the lower glacier is more dangerous due to melting snow bridges over crevasses while planes may not be able to land at base camp.” Climbers should book their expedition window to bracket the June 5-15 summit target — typically a 3-week expedition starting around May 25–30 and concluding by June 18–20.

K2’s climbing window is June through early August, with summit windows concentrating in late July and early August. Per Atlas & Boots: “The majority of expeditions on these mountains commence in June with summits taking place in late July / early August.” Per Explore: “Most climbs take place in July and August, per Summit Post, but June is the best option for those looking to avoid crowds without trading good conditions.” The Karakoram (K2, Nanga Parbat, Gasherbrums, Broad Peak) runs counter to the Himalayan calendar — while Nepal’s 8000ers are inaccessible during the June-August monsoon, Pakistan’s peaks experience their most stable weather windows in exactly this period. The Karakoram summit window is shorter and less predictable than Everest’s — often only 2-5 days of usable weather in a six-week expedition. Per Investigation 08, K2’s historical fatality rate (~12-25%) makes the weather window choice even more consequential than on Everest.

Manaslu can be climbed in both autumn and spring, but autumn (mid-September through mid-November) is the dominant commercial window for structural reasons. Per Outfitter Nepal: “Autumn is believed to be the best time to embark on the Manaslu Expedition… [the alternative] monsoon season (June through August) and winter (December through February) are the expedition’s most challenging and unsuccessful months.” Per Satori Adventures: “climbing in autumn is more comfortable and has high success rate due to the various factors. After the rainy and summer season, the temperature starts decreasing… Due to the starting of snow deposit rope fixing is easier. The temperate of Mt. Manaslu in the day time will be found mild for climbing.” The autumn window benefits from post-monsoon stability, fresh snow that makes rope fixing easier, and a temperature gradient that supports climbing without the extreme cold of late autumn or winter. Spring Manaslu is feasible but less successful — the spring rope-fixing is harder, the avalanche risk is higher coming out of winter, and the temperature swings can be more dramatic. Most operators (8K Expeditions, Highland Expeditions, Outfitter Nepal, Satori Adventures) run their primary Manaslu expeditions in autumn.

Kilimanjaro has two distinct dry seasons, both of which are climbing seasons. Per Ultimate Kilimanjaro: “The best time to climb Kilimanjaro is during the dry season – from December to mid March, and from late June to October. The best months are January, February, July, August, September and October.” Within these windows, Ian Taylor Trekking’s framework identifies February, July, and August as the three best months. February offers the warmest conditions with the least cloud cover. July and August are the busiest months — coinciding with US/European summer vacations — but offer the most reliable dry weather. September and October are excellent for climbers seeking fewer crowds with comparable weather. The months to avoid are April-May (long rains) and November (short rains). Per Climbing Kilimanjaro: “We avoid April and November as these are the main rainy seasons, making the trails more dangerous.” For full-moon climbs (popular for the visual experience on summit night), schedule the climb to start 4-5 days before the full moon date.

No — Everest has effectively one major commercial season and one minor one. Spring (April-May) is the dominant commercial window, with the May summit window producing the vast majority of all Everest summits historically. Autumn (September-October) is a much smaller secondary season — far fewer expeditions and lower success rates. Summer (June-August) is universally avoided due to the monsoon: heavy rainfall, avalanche risk, obscured visibility, and unstable snow conditions. Winter (December-February) is among the most dangerous pursuits in mountaineering per Global Rescue: “temperatures near -40°C and hurricane-force winds. Winter Everest ascents are extremely rare, demanding complete self-reliance due to limited rescue and helicopter access.” The jet stream sits directly atop Everest in winter, with sustained winds over 100 mph. A handful of winter ascents have been completed in history; commercial winter climbing does not exist as a viable category. For practical purposes, Everest is a May mountain, with an April approach and a small October secondary window.

The optimal Seven Summits sequence follows the calendar rather than fitness or difficulty progression. A typical 2-3 year campaign sequence: Year 1 — Kilimanjaro (any dry-season month, typically the start of the campaign as introduction), Aconcagua (February or December), Elbrus (June-August). Year 2 — Denali (June, after Aconcagua experience), Carstensz Pyramid (March or October). Year 3 — Vinson (December-January), Everest (May, typically last because of cost and risk). The calendar ordering produces natural fitness progression: Kilimanjaro at ~5,895m → Aconcagua at ~6,961m → Elbrus at 5,642m (technical refresher) → Denali at 6,190m (technical + endurance test) → Carstensz at 4,884m (technical rock) → Vinson at 4,892m (cold weather + remote logistics) → Everest at 8,849m (final objective). Per Investigation 02, the total cost is approximately $130,000-$250,000+ depending on operator selection. Most climbers take 3-7 years to complete the Seven Summits; 1-2 year compressed campaigns are physically possible but financially expensive and recovery-compressed. The choice of months across the campaign determines whether years are wasted on missed weather windows.