Weather is probably a major factor when you plan your trip to Nallathanniya, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually March and February, with an average temperature of 25°C, while the coldest months are January and February, with an average of 24°C. The rainiest months in Nallathanniya are November, October, May and September, with each month seeing an average of 427 mm of rainfall.