Other facts from our historical weather data: Which is the hottest month in Niamey? April has an average maximum temperature of 42°C (108°F) and is the hottest month of the year. Which is the coolest month in Niamey? The coolest month is January with an average maximum temperature of 32°C (90°F). Which is the wettest month in Niamey? August tops the wettest month list with 129mm (5.1 in) of rainfall. Which is the driest month in Niamey? January is the driest month with 0mm (0 in) of precipitation. Which is the sunniest month in Niamey? October is the sunniest month with an average of 285 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.