Sunnyvale Weather in January

The climate in Sunnyvale during January can be summarized as cool and a little damp.

January is in the winter in Sunnyvale and is typically the coldest month of the year. Daytime maximum temperatures average around a cool 14°C (57°F), whilst at night 5°C (40°F) is normal.

On average January is the wettest month of the year in Sunnyvale with around 87mm 3.4 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 9 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 Sunnyvale in January 2025.