Other facts from our historical weather data: Which months have the greatest rainfall in Khon Kaen? Most rainfall (rainy season) is seen in May, July, August and September. Does Khon Kaen have a dry season? Yes, the months of January, February and December are very dry. Which is the hottest month in Khon Kaen? April has an average maximum temperature of 38°C (100°F) and is the hottest month of the year. Which is the coolest month in Khon Kaen? The coolest month is January with an average maximum temperature of 31°C (88°F). Which is the wettest month in Khon Kaen? September tops the wettest month list with 256mm (10.1 in) of rainfall. Which is the driest month in Khon Kaen? December is the driest month with 6mm (0.2 in) of precipitation. Which is the sunniest month in Khon Kaen? March is the sunniest month with an average of 276 hours of sunshine. 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.