Planning for the weather is an important factor for making your trip to Jaffna a success, especially when you're splurging. The hottest months are usually April and May, with an average temperature of 29°C, while the coldest months are January and February, with an average of 27°C. The rainiest months in Jaffna are November, December, October and September, with each month seeing an average of 277 mm of rainfall.