Varanasi experience a humid subtropical climate ( Köppen climate classification Cwa ) with large variations between summer and winter temperatures . The dry summer starts in April and last until June , followed by the monsoon season from July to October . The temperature range between 22 and 46 ° C ( 72 and 115 ° F ) in the summers . Winters in Varanasi see very large diurnal variations , with warm days and downright cold nights . Cold waves from the Himalayan region cause temperatures to dip across the city in the winter from December to February and temperatures below 5 ° C ( 41 ° F ) are not uncommon . The average annual rainfall is 1 @,@ 110 mm ( 44 in ) . Fog is common in the winters , while hot dry winds , called loo , blow in the summers . In recent years , the water level of the Ganges have decreased significantly ; upstream dams , unregulated water extraction , and dwindling glacial sources due to global warming may be to blame .