Fountain Valley, CA climate is warm during summer when temperatures tend to be in the 70s and cool during winter when temperatures tend to be in the 50s.
The warmest month of the year is August with an average maximum temperature of 84.20 degrees Fahrenheit, while the coldest month of the year is December with an average minimum temperature of 46.00 degrees Fahrenheit.
Night & Day Variations
Temperature variations between night and day tend to be moderate during summer with a difference that can reach 20 degrees Fahrenheit, and moderate during winter with an average difference of 22 degrees Fahrenheit.
The annual average precipitation at Fountain Valley is 13.84 Inches. Rainfall in is fairly evenly distributed throughout the year. The wettest month of the year is January with an average rainfall of 3.18 Inches.