Other facts from our historical weather data: Which is the warmest month in Slaithwaite? 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 Slaithwaite? The coldest month is February with an average maximum temperature of 7°C (45°F). Which is the wettest month in Slaithwaite? August tops the wettest month list with 96mm (3.8 in) of rainfall. Which is the driest month in Slaithwaite? May is the driest month with 75mm (3 in) of precipitation. Which is the sunniest month in Slaithwaite? July is the sunniest month with an average of 175 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.