Vallejo (CA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Vallejo.
Climate overview of Vallejo
Temperatures in Vallejo, California, United States of America, vary greatly throughout the year. September is the hottest month at 27°C (81°F), while December is the coldest at 14°C (57°F).
Rainfall is modest, totalling around 477 mm (19 in) annually. The city experiences a distinct dry season from May to October, with warm summers and mild winters. December tends to be the wettest month. Sunshine peaks in May, when the city sees around 10.8 hours of sunshine per day.
Vallejo Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Vallejo - and find the best time to visit.
Monthly Temperature in Vallejo
The climate in Vallejo is known for significant temperature differences throughout the year, making the weather dynamic. Average maximum daytime temperatures range from a comfortable 27°C (81°F) in September, the warmest time of the year, to a moderate 14°C (57°F) during cooler months like December.
At night, you can expect temperatures ranging from 13°C (55°F) in September to around 4°C (39°F) during December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Vallejo
Vallejo maintains relatively dry conditions year-round, recording average annual precipitation of 477 mm (19 in). Significant seasonal changes in precipitation occur throughout the year. In the wettest month, December it receives high rainfall, averaging 101 mm (4 in) of precipitation, recorded across 12 rainy days. In contrast, the driest month August brings less rainfall, with 0.1 mm (0 in) over 0 rainy days. For more details, please visit our Vallejo Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Vallejo
Seasonal changes in sunshine hours are quite dramatic in Vallejo. While May receives considerable daily sunshine with up to 10.8 hours, December marks the darkest time of the year, where sunshine is scarce with only 5.3 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Vallejo by Month
The relative humidity is high throughout the year in Vallejo.
The city experiences its highest humidity in January, reaching 80%. In June, the humidity drops to its lowest level at 71%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit Vallejo
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: April, May, June, July, August, September and October
- Warmest weather: June, July, August and September
- Most sunshine: April, May, June and July
- Fewest rainy days: June, July, August and September
- Wettest months: January, February, March, April, November and December, when rainfall is highest.
- Seasonal pattern: A distinct dry season from May to October, with warm summers and mild winters
Frequently asked questions about the climate in Vallejo
What is the best time to visit Vallejo?
April, May, June, July, August, September and October typically offer the most optimal weather in Vallejo. In contrast, December tends to have less optimal conditions. Vallejo has a distinct dry season from May to October, with warm summers and mild winters.
What temperatures can I expect in Vallejo?
Daytime highs range from 14°C (57°F) in December to 27°C (81°F) in September. Nighttime lows range from 4°C (39°F) to 13°C (55°F). Temperatures vary considerably through the year.
How much rain does Vallejo get?
Annual rainfall is around 477 mm (19 in). December is the wettest month with 101 mm (4 in), while August is the driest with 0.1 mm (0 in).
How sunny is Vallejo?
Vallejo receives around 3,058 hours of sunshine per year. May is the sunniest month with 324 hours, while December is the cloudiest with just 160 hours. Overall, Vallejo enjoys abundant sunshine.
Vallejo 3-Day Forecast
Vallejo (CA) 3-Day Forecast
Vallejo on the map
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