March is often considered by experts to be the best time to go to Sri Lanka. With the best weather across the entire country at one time, lots of options open up for loads of variety in your holiday. Across the entirety of Sri Lanka, it is mainly hot and dry with little rainfall.
Sri Lanka in March  

In the south, Tea Country, Kandy, Nuwara Eliya and Horton Plains are at their most spectacular, with little rain and temperatures that average at about 25 °C. 

The east is getting much warmer now and wildlife in Yala National Park is excellent, with leopards enjoying the sunshine. Other game is around too, including buffalo, crocodiles and elephants, as well as lots of birds. Udawalawe is also great at this time, home to about 700 elephants, as well as 30 or so reptile species. In both Yala and Uda Walawe, camping is an excellent option at this time.

To finish with a bit of beach relaxation is always a good choice, and the beaches of the south east coast are continuing to warm, with the average temperatures now up to about 35 °C. Bentota, Galle, Tangalle, Weligama and Mirissa are fantastic options, Weligama especially if you want to see blue whales.

All things considered, March is a fantastic choice if you want to explore Sri Lanka throughout. Combine your wildlife safari with some beach and enjoy the wonderful culture. You should definitely experience the best of the sunshine it has to offer at this time.