Being close to the Bay of Bengal, the weather in Kolkata is greatly influenced by the sea. The city experiences a sub-tropical climate and remains warm and humid most of the year. Being near the sea, the Kolkata climate remains almost uniform all year round, although the city experiences the three main seasons of summer, monsoon, and winter.
Summer in Kolkata is hot and during this time the temperature can reach a maximum of 41° Celsius. March to June is considered as the summer months in Kolkata and May is often the hottest month. The average summer temperature here is between 24 to 38° Celsius. The city experiences high humidity during summer and the south-western monsoon winds blow during this season. Kolkata also receives certain amount of rainfall during the summer which increases the humidity, and the rains are often accompanied by dusty winds and thunderstorms.
Monsoon in Kolkata arrives around June and continues till the end of September. The southwest monsoons winds greatly impacts Kolkata and the city receives ample rains during the monsoon months. August usually receives the highest rainfall and the average annual rainfall that the city gets is around 1582 mm. The humidity also increases substantially during Monsoon time.
Winter in Kolkata is short. This is however the most comfortable season here and continues from December to February. During this time the temperature remains within 12° Celsius to 25° Celsius and is characterized by foggy mornings and chilly nights. The days are however quite bright and sunny with little rainfall, causing the humidity to reduce and the weather to remain warm and pleasant.
The best season to visit Kolkata is between October and March. During this time, the weather remains pleasant with comfortable temperatures. So visitors can roam around and explore the city while enjoying the festive atmosphere which prevails during this time.