Other facts from our historical weather data: When is the rainy season in Hpa-an? Rainy season in Hpa-an occurs in the months of May, June, July, August, September and October. Does Hpa-an have a dry season? Yes, the months of January, February and December are very dry. Which is the hottest month in Hpa-an? 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 Hpa-an? The coolest month is January with an average maximum temperature of 31°C (88°F). Which is the wettest month in Hpa-an? July tops the wettest month list with 841mm (33.1 in) of rainfall. Which is the driest month in Hpa-an? February is the driest month with 4mm (0.2 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.