Other facts from our historical weather data: Does Mayo have a dry season? Yes, the months of February and March are very dry. Which is the warmest month in Mayo? July has an average maximum temperature of 21°C (70°F) and is the warmest month of the year. Which is the coldest month in Mayo? The coldest month is January with an average maximum temperature of -19°C (-2°F). Which is the wettest month in Mayo? July tops the wettest month list with 65mm (2.6 in) of rainfall. Which is the driest month in Mayo? March is the driest month with 17mm (0.7 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.