Other facts from our historical weather data: When is summer in Chestertown?The hottest season / summer takes place in June, July, August and September. Which is the warmest month in Chestertown? July has an average maximum temperature of 31°C (88°F) and is the warmest month of the year. Which is the coldest month in Chestertown? The coldest month is February with an average maximum temperature of 6°C (43°F). Which is the wettest month in Chestertown? October tops the wettest month list with 138mm (5.4 in) of rainfall. Which is the driest month in Chestertown? February is the driest month with 66mm (2.6 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.