The Himalayas house the 3rd largest concentration of ice on the planet after the polar regions are often referred to as the third pole of the planet.
Seasons of Everest
Mount Everest lies 28° north of the equator and is subject to a typical northern hemisphere seasonal pattern. It lies at the edge of the influence of the Indian Monsoon which brings moisture and clouds from June to September. The cold months are December/January and the best trekking is between these two seasons, during March to May and September to November, when the climate is moderate.
1. Winter Weather at Everest:Winter weather (Nov to Feb) is dominated by the southward migration of the northern hemisphere jet stream which brings high winds, cold temperatures and on occasion heavy snow falls. Winter can be a great time for trekking as the trails are really quiet and there is something challenging about reachingEverest Base Campin the coldest time of year.
Day temperatures are comfortable with sunny skies generally prevailing although it can get well below freezing even as low as -20 nearEverest Base Camp.
2. Spring (preMonsoon)Weather at Everest:
March until the onset of the Monsoon is one of the ideal times to trek. Rain is infrequent and day temperatures are warm. Lots of trekkers and climbers are out in t-shirts and all in all it's a great time to trek.
3. Monsoon Season Everest:
The summer weather (June to August) is influenced by the Indian Monsoon which brings frequent rainfall and cloudy days. You might find solitude during this time but clouds and rain generally obscure the peaks and it’s not a good time to visit the Everest region.
4. Autumn Weather (post Monsoon) at Everest:
The Autumn season from the end of the Monsoon until temperatures get cold in December is a great time for trekking with generally clear days and comfortable temperatures.
Everest Precipitation Patterns
TheEverest Base CampRegion is fairly dry with an average of 18 inches of precipitation received at base camp. Most of the precipitation that does fall (80%+) occurs during the monsoon season of June to August and the rest of the year is fairly dry.
Monsoon moisture comes from a south so Everest Base Camp experiences a rain shadow effect with most precipitation falling on the south side of the mountains with the rain almost running out of steam as it were, before the clouds reach base camp.
The high elevation and generally cold temperature act as a controlling influence on the amount of moisture and limit its overall availability. This becomes evident when one compares base camp precipitation (18in) to that in Lukla (70in) at the start of the trek.
The actual summit of Everest receives very little precipitation as most of it is scoured by high winds which you can see sometimes with the spindrift on the summit.
Big winter snowstorms while infrequent are possible as strong mid-latitude storms occasionally brush the region and can deliver over a meter of snow at base camp often taking trekkers by surprise. Its still possible to hike out but be prepared with windproof bottoms and gaiters if planning a winter trek. Ohh and don't forget the down jacket of course.
Temperatures at Everest Base Camp
The coldest temperatures of the year occur from the 15th of December onward until the end of January with temperatures at the summit averaging -37C (-35F) while those at Everest Base Camp average -17C (1.4F). Temperatures warm rapidly in the spring months of April and May bringing t-shirt weather although nights are still cold and chilly. It’s not uncommon to see climbers wearing t-shirts all the way up to camp 3 during this time period.
