Other facts from our historical weather data: Which is the warmest month in Stanley? 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 Stanley? The coldest month is December with an average maximum temperature of 7°C (45°F). Which is the wettest month in Stanley? October tops the wettest month list with 106mm (4.2 in) of rainfall. Which is the driest month in Stanley? April is the driest month with 72mm (2.8 in) of precipitation. Which is the sunniest month in Stanley? May is the sunniest month with an average of 193 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.