Other facts from our historical weather data: Which months have the greatest rainfall in Surin? Most rainfall (rainy season) is seen in May, July, August and September. Does Surin have a dry season? Yes, the months of January, February and December are very dry. Which is the hottest month in Surin? April has an average maximum temperature of 37°C (99°F) and is the hottest month of the year. Which is the coolest month in Surin? The coolest month is January with an average maximum temperature of 31°C (88°F). Which is the wettest month in Surin? September tops the wettest month list with 275mm (10.8 in) of rainfall. Which is the driest month in Surin? January is the driest month with 8mm (0.3 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.