Other facts from our historical weather data: Which is the warmest month in Rosslare? 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 Rosslare? The coldest month is February with an average maximum temperature of 10°C (50°F). Which is the wettest month in Rosslare? November tops the wettest month list with 125mm (4.9 in) of rainfall. Which is the driest month in Rosslare? May is the driest month with 61mm (2.4 in) of precipitation. Which is the sunniest month in Rosslare? May is the sunniest month with an average of 213 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.