Pleasant sub-alpine climate prevails in the hills. The plains however experience tropical climate making them uncomfortably humid especially during the rainy seasons. Winter sets in from around the end of the month of October and lasts till the end of February. The temperature drops to a minimum of 6 to 80 Celsius, the nights and early mornings are foggy, and rain is scanty. Summer arrives in the middle of May accompanied by high humidity and rainfall. The temperature reaches a maximum of 35 to 380 Celsius. The frequent rains however serve to push the mercury down. The Monsoons blow full blast during the month of June. Thunder storms known as Bordoichilla is a frequent occurrence during the afternoons. Spring and Autumn with moderate temperatures and modest rainfall are the best seasons.
Assam falls in a zone prone to earthquakes. Though mild tremors are familiar to the region, high-intensity earthquakes are rather infrequent. However, they do occur as in 1869 when the bank of the Barak sank by 15 ft, in 1897, and again in 1950 when a large part of the State was ravaged by an earthquake of unprecedented intensity.