Other facts from our historical weather data: Which is the warmest month in Saint Hilary? August has an average maximum temperature of 19°C (66°F) and is the warmest month of the year. Which is the coldest month in Saint Hilary? The coldest month is February with an average maximum temperature of 11°C (52°F). Which is the wettest month in Saint Hilary? November tops the wettest month list with 110mm (4.3 in) of rainfall. Which is the driest month in Saint Hilary? June is the driest month with 62mm (2.4 in) of precipitation. Which is the sunniest month in Saint Hilary? May is the sunniest month with an average of 222 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.