San Mateo County (San Mateo)
May
Weather in San Mateo County, California for May 2026
Your guide to San Mateo County weather in May - trends and predictions
In general, the average temperature in San Mateo County at the beginning of May is 16.1 °F. As the month progressed, temperatures tended to remain steady, reaching an average of 16.1 °F by the end of May.
Precipitation in San Mateo County during May is a rare event, with an average of fewer than 2 rainy days.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
30
Dry days
1
Rainy days
0
Snow days
16°/10°
Temperatures
20 km/h
Avg max wind
83 %
Avg humidity
San Mateo County Weather May
Move between months or click on a day
Temperatures trend during May in San Mateo County
See the weather trend as well as the moving average line
May weather in San Mateo County day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| May 1 |  Overcast | 15° /9° | 0 mm | 4 | |
| May 2 | Overcast | 13° /9° | 0 mm | 3 | |
| May 3 | Overcast | 12° /10° | 0.1 mm | 3 | |
| May 4 |  Partly cloudy | 16° /9° | 0 mm | 5 | |
| May 5 |  Sunny | 22° /13° | 0 mm | 6 | |
| May 6 | Partly cloudy | 19° /11° | 0 mm | 5 | |
| May 7 | Overcast | 16° /10° | 0 mm | 4 | |
| May 8 | Overcast | 18° /9° | 0 mm | 4 | |
| May 9 | Overcast | 20° /10° | 0 mm | 5 | |
| May 10 | Overcast | 18° /11° | 0 mm | 4 | |
| May 11 | Overcast | 14° /10° | 0 mm | 3 | |
| May 12 |  Heavy rain at times | 14° /10° | 4 mm | 3 | |
| May 13 | Overcast | 15° /10° | 0.1 mm | 4 | |
| May 14 | Overcast | 17° /9° | 0 mm | 4 | |
| May 15 | Overcast | 17° /10° | 0 mm | 4 | |
| May 16 | Overcast | 17° /10° | 0 mm | 4 | |
| May 17 | Overcast | 15° /11° | 0 mm | 4 | |
| May 18 |  Cloudy | 19° /9° | 0 mm | 4 | |
| May 19 | Partly cloudy | 20° /11° | 0 mm | 6 | |
| May 20 | Overcast | 16° /9° | 0 mm | 4 | |
| May 21 | Overcast | 18° /8° | 0 mm | 4 | |
| May 22 | Overcast | 15° /10° | 0 mm | 4 | |
| May 23 | Overcast | 13° /9° | 0 mm | 3 | |
| May 24 | Overcast | 13° /9° | 0 mm | 3 | |
| May 25 | Overcast | 11° /9° | 0 mm | 3 | |
| May 26 | Overcast | 16° /10° | 0 mm | 4 | |
| May 27 |  Mist | 16° /9° | 0 mm | 4 | |
| May 28 | Mist | 13° /10° | 0 mm | 3 | |
| May 29 | Mist | 18° /10° | 0 mm | 4 | |
| May 30 | Mist | 20° /11° | 0 mm | 5 | |
| May 31 | Mist | 19° /10° | 0 mm | 4 | |
| Next | |||||
Important Notice
Our weather forecast for San Mateo County in May is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the San Mateo County forecast closer to your planned date for the most up-to-date weather information.
Change Month
San Mateo County in May - FAQ
What are the expected maximum and minimum temperatures in San Mateo County during May?
Enjoy moderate daytime temperatures of up to 16° and cooler nights around 10°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in San Mateo County during May?
Rainfall in San Mateo County during May is rare to nonexistent, with the total expected rainfall being less than 10 mm and approximately 1 days seeing any precipitation. Planning without the concern for rain is generally straightforward during this very dry period.
What are the typical wind conditions in San Mateo County during May?
The average wind speed in San Mateo County during May is 20 km/h, suggesting breezy to windy conditions, depending on your activities.
May rainfall patterns in San Mateo County
Explore the daily rainfall trends and prepare for San Mateo Countys May weather 💧
UV exposure in San Mateo County during May
Stay informed about UV levels for safe outdoor activities throughout the month of May ☀️
Top locations in San Mateo County
Select a location for an accurate weather forecast
More Locations Quick links
More San Mateo County weather pages
You are here
Where is San Mateo County?Get accurate weather forecasts for San Mateo County, located at latitude 37.563 and longitude -122.326. Stay updated with localized weather information tailored for San Mateo County.
Found a mistake?
We appreciate your attention to details. Tell us here.