Other facts from our historical weather data: Which is the warmest month in Darwen? July has an average maximum temperature of 20°C (68°F) and is the warmest month of the year. Which is the coldest month in Darwen? The coldest month is February with an average maximum temperature of 8°C (46°F). Which is the wettest month in Darwen? December tops the wettest month list with 121mm (4.8 in) of rainfall. Which is the driest month in Darwen? April is the driest month with 82mm (3.2 in) of precipitation. Which is the sunniest month in Darwen? May is the sunniest month with an average of 187 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.