Other facts from our historical weather data: Which months have the greatest rainfall in Garlieston? Most rainfall (rainy season) is seen in October and November. Which is the warmest month in Garlieston? August has an average maximum temperature of 18°C (64°F) and is the warmest month of the year. Which is the coldest month in Garlieston? The coldest month is February with an average maximum temperature of 9°C (48°F). Which is the wettest month in Garlieston? October tops the wettest month list with 155mm (6.1 in) of rainfall. Which is the driest month in Garlieston? May is the driest month with 80mm (3.1 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.