Characteristics of Precipitation in Nepal

• Two patterns of monsoon seasons:

–Summer monsoon (easterlies)

–Winter monsoon (westerlies)

• Summer monsoon advance from Bay of Bangal to the west; more than 80% of total rainfall occurs during June-September.
• Usually, western parts receive lesser amount of rainfall than the east during summer monsoon due to decreased moisture gradient in the wind approaching from the east.
• The winter monsoon originating from the Arabian Sea usually brings cold air and modest precipitation along the northwest regions.
• Mean annual precipitation of Nepal ranges from 100mm to 5000mm and mean summer precipitation ranges from 25mm to 4500mm.