Castro Valley Weather in January

The climate in Castro Valley during January can be summarized as cool and damp.

January is in the winter in Castro Valley and is typically the coldest month of the year. Daytime maximum temperatures average around a cool 13°C (56°F), whilst at night 4°C (40°F) is normal.

On average January is the wettest month of the year in Castro Valley with around 107mm 4.2 inches of rain making it a damp 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 6.2 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 Castro Valley in January 2024.