Other facts from our historical weather data: Which months have the greatest rainfall in Tweng? Most rainfall (rainy season) is seen in June, July and August. When is winter in Tweng? The coldest season / winter is in the following months: January, February and December. Which is the warmest month in Tweng? 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 Tweng? The coldest month is January with an average maximum temperature of -2°C (28°F). Which is the wettest month in Tweng? June tops the wettest month list with 164mm (6.5 in) of rainfall. Which is the driest month in Tweng? January is the driest month with 78mm (3.1 in) of precipitation. Which is the sunniest month in Tweng? July is the sunniest month with an average of 196 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.