The climate of Nepal differs from its geography. Nepal is a very small country having multi climatic diverse. The altitude of Nepal begins from 70 meters to top of the world (8848) meter from sea level. The Tarai region which lies in a tropical southern part of Nepal has humidity and hot. The hilly regions are pleasurable and mountain regions are cold and freezing some places. There is four climatic season of Nepal.
1: Spring: March-May (Rhododendron blooms, cool and beautiful weather)
2: Summer: June-August (Rainy season of Nepal, hot weather, lush green vegetation)
3: Autumn: September-November (Best time to visit having a view of mountains, fantastic weather)
4: Winter: December-February (Night time is cold, snowy in mountain region)
Nepal has Sub-tropical Monsoon type of climate. But the climatic condition varies considerably from one place to another place. Chief Factors affecting climate are:
1: Altitude: Temperature decreases at a general lapse rate of 6 at every 1000m ascent.
2: Slope and Direction of the mountains South facing slope records high temperature and receive more rainfall as compared to north facing ones.
Three distinct Seasons
1: Cold or Winter Season: October to January
2: Hot or Summer Season: February to May
3: Hot-Wet or Rainy Season: June to September
Mountain Trekking or Climbing Season
1: Pre-Monsoon (spring season)-March April, May, and Mid June
2: Post-Monsoon (autumn) - September, October, November and Mid December
A: Sub Tropical Monsoon belt
Tarai, Inner Tarai, Churia (Area up to 1200m)
Summer temperature 34-39 c. Temperature increases from the east toward the west.
Winter Temperature 6 c -9c
Average rainfall 1oo-2oocm
B: Warm Temperature Monsoon Belt
This belt occupies Hills and valleys areas of 1200to 21oom above sea level. Summer temperature is between 24 and 30 c and winter temperature is about 5 c. In winter fogs are common. Rainfall: 1oo-123cm
C: Cool Temperature Monsoon Belt
This belt occupies higher elevation of Mahabharat range and lower elevation of Inner Himalayas (2100-33oocm). Summer Temperature is between 15 c and 20 c. winter temperature is around 0 c. Rainfall 5o-1oocm.
D: Alpine Climatic Belt
This belt occupies higher elevation of Inner Himalaya and lowers elevation of the Greater Himalaya (33oo-5ooom).
Summer Temperature -10 c -15 c, Winter Temperature -5 c -10 c and Rainfall less than 5o cm
E: Tundra Climatic Belt
The area over a 5000m temperature of constantly far below 0 c. Air is thin and snow, storms in the afternoon are very frequent. Precipitation occurs in the form of snow. extremely cold.