Nepal’s varied topography of plains, hills and mountains result in an equally varied climate divided into five zones – Arctic, sub-Arctic, cold, temperate and sub-tropical/tropical – and five seasons, spring, summer, monsoon, fall and winter. Overall, most of the country’s rainfall occurs in the June to early September monsoon season. High summer sees extreme heat; winters everywhere except the plains are snowy and freezing, and spring and fall are warm and pleasant.
The five climate zones in Nepal are based on the vast range of altitudes over a comparatively short north-south distance and the Himalayan massifs influence conditions. The southern plains of the Terai along the border of India see tropical and sub-tropical weather. Summer temperatures soar to 113°F, and winters are warm at worst. The summer monsoon hits here first, with dramatic storms causing landslides and flooding.
The Kathmandu Valley has nice summers with temperatures around 77°F and spring and fall highs a few degrees lower. Winter is cold, with temperatures regularly dropping around freezing with morning fog. The monsoon season brings high humidity and around 1300 mm of rain. Pokhara lies in the center of Nepal and enjoys a sub-tropical climate with its elevation restricting weather to a moderate average of 86°F in summer and 36°F or higher in winter.
Best Time to Visit Nepal
The monsoon season is the worst time to be here for trekking and hiking, as the intense rains turn trails to leech-infested mud pools and the clouds tend to obscure view of the towering mountains. However, the monsoon here isn’t typical, as rain often falls at night, with the sky clearing by morning and the mountains sparkling in the distance. Mustang, Dolpo and Manang regions are within the rain-shadow area and deflect the clouds, making outdoor activities possible even during the monsoon season.
Spring and fall are the best times to visit Nepal weather-wise, with warm nights and sunny days the general rule. For outdoor activities, the short period between mid-September and late November and early March to mid-May are best, but rates in the better hotels may be more expensive as it is peak season.