San Mateo (CA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit San Mateo.
Climate overview of San Mateo
San Mateo, California, United States of America, has a moderate seasonal temperature range, with September reaching 24°C (75°F) and December cooling to 15°C (59°F).
With around 415 mm (16 in) of annual rainfall, San Mateo has a fairly dry climate. However, it has a distinct dry season from May to November. The wettest month is December, while July sees the least rain. The sunniest month is May, with 10.8 hours of sunshine per day on average.
San Mateo Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in San Mateo - and find the best time to visit.
Monthly Temperature in San Mateo
In San Mateo, seasonal changes bring about a moderate variation in temperatures. Average daytime temperatures reach a comfortable 24°C (75°F) in September. In December, the coolest month of the year, temperatures drop to a moderate 15°C (59°F).
At night, temperatures range from around 14°C (57°F) in September to 6°C (43°F) in December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in San Mateo
San Mateo typically sees modest rainfall throughout the year, with an average annual precipitation of 415 mm (16 in). San Mateo can be quite wet during December, receiving approximately 99 mm (3.9 in) of precipitation over 13 rainy days.
In contrast, during the driest month (July), you will experience much drier conditions, with 0 mm (0 in) of precipitation spread across 0 rainy days. For more details, please visit our San Mateo 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 San Mateo
San Mateo can be enjoyed more throughout the sunniest month of May under a blue sky, with approximately 10.8 hours of sunshine daily. In contrast, the city experiences much darker days in December, 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
Water Temperature in San Mateo
The mean water temperature over the year ranges from 12°C (54°F) in January to 14°C (57°F) in June.
Water temperature over the year
Humidity in San Mateo by Month
The relative humidity is high throughout the year in San Mateo.
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
Wind Speed in San Mateo
The average wind speed over the year ranges from 3 m/s (6 knots) to 7 m/s (14 knots). It is lower in January, November and December and higher in June and July. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit San Mateo
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, June, July, August, September and October
- Warmest weather: July, August and September
- Most sunshine: April, May, June and July
- Fewest rainy days: June, July, August and September
- Seasonal pattern: A distinct dry season from May to November
Frequently asked questions about the climate in San Mateo
What is the best time to visit San Mateo?
May, June, July, August, September and October typically offer the most optimal weather in San Mateo. In contrast, January, February and December tend to have less optimal conditions. San Mateo has a distinct dry season from May to November.
What temperatures can I expect in San Mateo?
Daytime highs range from 15°C (59°F) in December to 24°C (75°F) in September. Nighttime lows range from 6°C (43°F) to 14°C (57°F).
How much rain does San Mateo get?
Annual rainfall is around 415 mm (16 in). December is the wettest month with 99 mm (3.9 in), while July is the driest with 0 mm (0 in).
How sunny is San Mateo?
San Mateo 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, San Mateo enjoys abundant sunshine.
San Mateo 3-Day Forecast
San Mateo (CA) 3-Day Forecast
San Mateo on the map
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