Sri Lanka is a small island there are different variation of climate. Sri Lanka have two monsoons which can effect the whole country .also best time to travel will be depends on where you wants to travel .
North east monsoon generally can effect the whole island and this comes December to February.
Southwest monsoon will be May to September .and this will be less intense and impacts the south west coast and hill country.
Most famous travel destinations in Sri Lanka.
Southern part in Sri Lanka
Travelers who wish to travel Bentota , Ambalangoda , Galle , Thangalle and Yala the best time is December to April .during this time it’s a very very little rain but mostly dry during this time
East coast of Sri Lanka
during April /may to september is the best time visit arugambay and trincomalee beaches .travellers can enjoy as much as they wants without any troubles .
Central part of Sri Lanka
We highly recommended that during january to april is the best time travel kandy .dambulla, nuwareliya
North central province in Sri Lanka
Every traveller can plan their visits during november to april in anuradhapura ,habarana ,polonnarwa cities .its very nice and sunny in this time of the year
North west part of Sri Lanka
October to May is the best time to travel to north west ,Chillaw, Kalpitiya and etc..its great time to windsurfing ,kayaking ,snorkeling and many more
North province in Sri Lanka
Travellers who like to visit nothern part of sri lanka january to september would be the best time to travel around jaffana. Jaffana is the culture capital of tamil population in sri lanka .
The best tourists season is in Sri Lanka November to April .however in general Sri Lanka is an Amazing Destination to travel whole around the year .