Explanation:

 The monsoon season in West Bengal is much awaited as the landscape turns lush green after the monsoon showers. By the middle of June, monsoon approaches the state and it is influenced by the winds blowing from Bay of Bengal.The climates of West Bengal are influenced most by the gigantic wet monsoon air stream coming from the south and south-east. Mid-June to September is a rainy spell. To quench the thirst of dry summer, a gigantic air-stream with rain-bearing low black clouds arrives and bursts with a heavy downpour. Very often they are cyclonic with high wind speeds. The Bay cyclones are the most furious of all cyclones. In Bengal the wet monsoon current comes mainly from the south and south-east. For 3.5 months moderate to heavy rains occur, with sunny breaks and cyclonic bursts. Sometimes it continues for a week.