Nepal boasts a wide variety of climatic conditions, depending on the season and its unique geography. Even within the same season, the weather can be phenomenally different depending on whether you are trekking in the lowland Terai, the mid-hills, or the high Himalayas. In general, the country has four clear seasons. Autumn, from mid-September to November, is the clearest and most comfortable season and also the best time for trekking in Nepal. Winter begins late in November and continues until March, bringing the coldest temperatures of the year, especially in the mountains. Spring. Which occurs between March and May, is another high trekking season and is best for trips to high-altitude mountains such as Everest, Lhotse, and Makalu, as the weather is stable and the hills are blanketed with rhododendrons in full bloom. The summer, between June and September, falls during the monsoon when the rains are heavy and traveling is tough, but also transforms the landscape into lush greenery, misty valleys, and colorful forests.
Geographical Influence on Nepal's Climate
Nepal's geographical composition is a key determinant of its climate. Being a comparatively small country, the nation experiences huge and contrasting altitudinal variations, from the low-lying Terai planes at an altitude of just 60 meters above sea level to the huge Himalayas with over 8,000 meters of altitude. This huge variation brings tremendous climatic contrasts within short distances.
- Terai Region (60m – 600m): The Indian border southern belt has a hot humid subtropical climate. It's warmest in summer with temperatures of up to 40°C, with mild winters. It is given to heavy monsoon rains in the months of June, July, and September.
- Hill Region (600m – 3,000m): This area consists of Kathmandu, Pokhara, and mid-hill villages and features a moderate climate with hot summers, cold winters, and milder conditions. Although heavy rains occur during the monsoon season, there is comfortable weather during spring and autumn for trekking.
- Himalayan Region (Above 3,000m): The higher Himalayas face alpine and tundra climates. It is extremely cold, and it snows during winter. Beyond 5,000m, it is extremely cold and dry, with little vegetation and oxygen supply, and trekkers require acclimatization.
Seasonal Patterns of Weather in Nepal
Spring (March – May)
Spring is also a good time to travel to Nepal. The weather is mild with hot days and freezing nights, and the sights are just great with picturesque views of the snow-covered mountains. The forests and hills burst into rhododendrons, wildflowers, and leaves. Hill temperatures range from 16°C to 23°C, while the higher reaches are chilly but bearable. This is perfect time for trekking in regions like Annapurna, Langtang, and Everest since trails are green and skies are mostly clear.
Summer/Monsoon (June – August)
Monsoon rains cause heavy rainfall, especially in hills and Terai, and trails get slippery and landslide conditions. Clouds typically obscure mountain views and leeches populate lower-altitude forests. But rain also provides fertility to the ground, and the country becomes green and rivers full, which can be beautiful to behold. Trekking can still be accomplished in rain-shadow places like Mustang and Dolpo as these receive very little rainfall. Mean temperatures range from 18°C to 30°C in the majority of trekking areas, but there is high humidity.
Autumn (September – November)
Autumn is the peak trekking season in Nepal. Monsoon removes the dust and fogs and brings clean air and clear sight of the Himalayas. Sunny and warm by day, cool at night, and mostly stable conditions make it ideal for trekking and climbing. Temperatures in major trekking regions are on average 15°C to 24°C during the day. This season also coincides with Nepal's biggest festivals, Dashain and Tihar, so visitors have an opportunity to observe vibrant cultural events along with their trek.
Winter (December – February)
Winter is cold, arid weather, especially at high Himalayan altitudes where heavy snowfall may shut mountain passes like Thorong La or Larkya La. Hill temperatures fall significantly below the freezing point, while the weather in Kathmandu and mid-hills is pleasant and sunny (8°C to 15°C). There remains trekkable weather at lower altitudes such as Ghorepani Poon Hill, Langtang Valley, and Helambu with fewer trekkers and blue skies. If trekkers are willing to endure cold, winter holds secrets for them in the solitude and unspoiled mountain scenery.