Other facts from our historical weather data: Which is the hottest month in Guarajuba? January has an average maximum temperature of 32°C (90°F) and is the hottest month of the year. Which is the coolest month in Guarajuba? The coolest month is August with an average maximum temperature of 28°C (82°F). Which is the wettest month in Guarajuba? May tops the wettest month list with 148mm (5.8 in) of rainfall. Which is the driest month in Guarajuba? December is the driest month with 48mm (1.9 in) of precipitation. Which is the sunniest month in Guarajuba? January is the sunniest month with an average of 246 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.