Other facts from our historical weather data: Which is the warmest month in De Kooy? August has an average maximum temperature of 21°C (70°F) and is the warmest month of the year. Which is the coldest month in De Kooy? The coldest month is February with an average maximum temperature of 7°C (45°F). Which is the wettest month in De Kooy? October tops the wettest month list with 108mm (4.3 in) of rainfall. Which is the driest month in De Kooy? April is the driest month with 45mm (1.8 in) of precipitation. Which is the sunniest month in De Kooy? May is the sunniest month with an average of 224 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.