Other facts from our historical weather data: When is the rainy season in Kompong Thom? Rainy season in Kompong Thom occurs in the months of May, June, July, August, September and October. Does Kompong Thom have a dry season? Yes, the months of January and February are very dry. Which is the hottest month in Kompong Thom? March has an average maximum temperature of 37°C (99°F) and is the hottest month of the year. Which is the coolest month in Kompong Thom? The coolest month is January with an average maximum temperature of 33°C (91°F). Which is the wettest month in Kompong Thom? September tops the wettest month list with 299mm (11.8 in) of rainfall. Which is the driest month in Kompong Thom? January is the driest month with 11mm (0.4 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.