Nepal has five climatic zones, broadly corresponding to the altitudes. The tropical and subtropical zones lie below 1,200 meters (3,937 ft.), the temperate zone 1,200 to 2,400 meters (3,937 to 7,874 ft.), the cold zone 2,400 to 3,600 meters (7,874 to 11,811 ft.), the subarctic zone 3,600 to 4,400 meters (11,811 to 14,436 ft.), and the Arctic zone above 4,400 meters (14,436 ft.)
In the Terai (south Nepal), summer temperatures exceed 37° C and higher in some areas, winter temperatures range from 7°C to 23°C in the Terai. In mountainous regions, hills and valleys, summers are temperate while winter temperatures can plummet under subzero. The Kathmandu Valley has a pleasant climate with average summer and winter temperatures of 19°C – 35°C and 2°C – 12°C respectively.
- Winter: December-February
- Spring: March-May
- Summer: June-August
- Autumn: September-November.
- Monsoon: June till mid-September
- Low Season (Jun–Sep)
The monsoon rains (mostly at night) bring landslides, and clouds often obscure mountain views. Rain, mud and leeches deter most trekkers, but hefty hotel discounts are common and this is a popular time to travel overland to Tibet.
- Shoulder (Mar–Apr)
The second-best time to visit and trek, spring brings warm weather and spectacular rhododendron blooms.
- High Season (Oct–Nov)
Clear skies and warm days make autumn the peak season. Thousands of people hit the trails in the Everest and Annapurna regions, accommodation in Kathmandu gets booked up and prices peak.
Average temperatures and rainfall during peak summer and winter in three most popular tourist areas:
|Place||Summer (May, Jun , July)||Winter (Dec, Jan, Feb)|
|Max (°C)||Min (°C)||Rain (mm)||Max (°C)||Min (°C)||Rain (mm)|