Other facts from our historical weather data: When is winter in Hvammstangi? The coldest season / winter is in the following months: January, February, March and December. Which is the warmest month in Hvammstangi? August has an average maximum temperature of 13°C (55°F) and is the warmest month of the year. Which is the coldest month in Hvammstangi? The coldest month is February with an average maximum temperature of 2°C (36°F). Which is the wettest month in Hvammstangi? September tops the wettest month list with 116mm (4.6 in) of rainfall. Which is the driest month in Hvammstangi? June is the driest month with 59mm (2.3 in) of precipitation. 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.