Other facts from our historical weather data: Which is the warmest month in Middleton in Teesdale? July has an average maximum temperature of 19°C (66°F) and is the warmest month of the year. Which is the coldest month in Middleton in Teesdale? The coldest month is February with an average maximum temperature of 6°C (43°F). Which is the wettest month in Middleton in Teesdale? December tops the wettest month list with 99mm (3.9 in) of rainfall. Which is the driest month in Middleton in Teesdale? March is the driest month with 74mm (2.9 in) of precipitation. Which is the sunniest month in Middleton in Teesdale? May is the sunniest month with an average of 183 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.