When travelling, it's generally smart to pack in preparation for rain or any other conditions that may arise. The rainfall in Benbecula is roughly greater than that of Calcutta. You can assume this to be the case over the next 12 days.
We forecast the temperature to be around the 36 °Cs in April, on average. The temperature in Calcutta is generally hotter than in Benbecula. Book flights in a timely manner in correlation to your departure date.