Other facts from our historical weather data: Does Garissa have a dry season? Yes, the months of February, May, June, July, August and September are very dry. Which is the hottest month in Garissa? March has an average maximum temperature of 37°C (99°F) and is the hottest month of the year. Which is the coolest month in Garissa? The coolest month is August with an average maximum temperature of 32°C (90°F). Which is the wettest month in Garissa? November tops the wettest month list with 82mm (3.2 in) of rainfall. Which is the driest month in Garissa? July is the driest month with 4mm (0.2 in) of precipitation. Which is the sunniest month in Garissa? May is the sunniest month with an average of 282 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.