Other facts from our historical weather data: Which months have the greatest rainfall in Polonnaruwa? Most rainfall (rainy season) is seen in October, November and December. Which is the hottest month in Polonnaruwa? May has an average maximum temperature of 36°C (97°F) and is the hottest month of the year. Which is the coolest month in Polonnaruwa? The coolest month is February with an average maximum temperature of 30°C (86°F). Which is the wettest month in Polonnaruwa? November tops the wettest month list with 246mm (9.7 in) of rainfall. Which is the driest month in Polonnaruwa? June is the driest month with 20mm (0.8 in) of precipitation. No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.