Weather is probably a major factor when you plan your trip to Nalagasdeniya, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually March and April, with an average temperature of 27°C, while the coldest months are January and February, with an average of 27°C. The rainiest months in Nalagasdeniya are May, November, September and October, with each month seeing an average of 333 mm of rainfall.