Other facts from our historical weather data: Which months have the greatest rainfall in Portnoo? Most rainfall (rainy season) is seen in January, October, November and December. Which is the warmest month in Portnoo? 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 Portnoo? The coldest month is February with an average maximum temperature of 9°C (48°F). Which is the wettest month in Portnoo? December tops the wettest month list with 176mm (6.9 in) of rainfall. Which is the driest month in Portnoo? April is the driest month with 100mm (3.9 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.