Other facts from our historical weather data: Which is the warmest month in Stromness? August has an average maximum temperature of 15°C (59°F) and is the warmest month of the year. Which is the coldest month in Stromness? The coldest month is February with an average maximum temperature of 8°C (46°F). Which is the wettest month in Stromness? November tops the wettest month list with 139mm (5.5 in) of rainfall. Which is the driest month in Stromness? May is the driest month with 62mm (2.4 in) of precipitation. Which is the sunniest month in Stromness? May is the sunniest month with an average of 192 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.