Petaluma Weather in December

The climate in Petaluma during December can be summarized as cool and wet.

December is in the winter in Petaluma and is typically the 2nd coldest month of the year. Daytime maximum temperatures average around a cool 14°C (56°F), whilst at night 3°C (38°F) is normal.

On average December is the 2nd wettest month of the year in Petaluma with around 145mm 5.7 inches of rain making it a wet time to visit. This rainfall is typically spread over 10 days, although this may vary considerably.

On the flip side this corresponds to an average of 5.6 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Petaluma in December 2024.