Other facts from our historical weather data: When is the rainy season in Long Beach? Rainy season in Long Beach occurs in the months of January, February, March, October, November and December. Which is the warmest month in Long Beach? August has an average maximum temperature of 19°C (66°F) and is the warmest month of the year. Which is the coldest month in Long Beach? The coldest month is December with an average maximum temperature of 9°C (48°F). Which is the wettest month in Long Beach? November tops the wettest month list with 302mm (11.9 in) of rainfall. Which is the driest month in Long Beach? July is the driest month with 28mm (1.1 in) of precipitation. Which is the sunniest month in Long Beach? July is the sunniest month with an average of 330 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.