San Mateo County (San Mateo)
October
Weather in San Mateo County, California for October 2026
Your guide to San Mateo County weather in October - trends and predictions
So far, October 2026 in San Mateo County is slightly warmer than the historical average by 1.2 °C.
The forecast for the next days in San Mateo County predicts temperatures to be around 18 °C, close to the historical average.
In general, the average temperature in San Mateo County at the beginning of October is 23.9 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 18 °C by the end of October.
With an average of 2 rainy days, San Mateo County experiences minimal rainfall in October.
Is October a good time to visit San Mateo County? check out the best time to travel to San Mateo County page.
✨ Is October a good time to visit San Mateo County? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
29
Dry days
2
Rainy days
0
Snow days
20°/13°
Temperatures
15 km/h
Avg max wind
72 %
Avg humidity
San Mateo County Weather October
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Temperatures trend during October in San Mateo County
See the weather trend as well as the moving average line
October weather in San Mateo County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Oct. 1 |  Moderate rain | 25° /15° | 16 mm | 6 | |
| Oct. 2 |  Sunny | 24° /15° | 0 mm | 4 | |
| Oct. 3 | Sunny | 22° /14° | 0 mm | 5 | |
| Oct. 4 |  Overcast | 23° /16° | 0 mm | 4 | |
| Oct. 5 |  Partly cloudy | 23° /16° | 0 mm | 5.8 | |
| Oct. 6 |  Cloudy | 25° /16° | 0 mm | 5 | |
| Oct. 7 | Cloudy | 25° /16° | 0 mm | 5.6 | |
| Oct. 8 | Overcast | 21° /14° | 0 mm | 4 | |
| Oct. 9 | Overcast | 19° /13° | 0 mm | 4 | |
| Oct. 10 | Overcast | 18° /12° | 0 mm | 4 | |
| Oct. 11 | Overcast | 17° /11° | 0 mm | 4 | |
| Oct. 12 | Overcast | 17° /12° | 0 mm | 4 | |
| Oct. 13 | Moderate rain | 19° /12° | 12.5 mm | 4 | |
| Oct. 14 | Overcast | 17° /11° | 0.4 mm | 4 | |
| Oct. 15 | Overcast | 19° /13° | 0 mm | 4 | |
| Oct. 16 |  Patchy rain possible | 19° /13° | 0.3 mm | 4 | |
| Oct. 17 | Overcast | 21° /12° | 0 mm | 4 | |
| Oct. 18 | Sunny | 21° /12° | 0 mm | 4 | |
| Oct. 19 | Sunny | 19° /13° | 0 mm | 4 | |
| Oct. 20 | Sunny | 22° /12° | 0 mm | 4.5 | |
| Oct. 21 | Overcast | 20° /13° | 0.3 mm | 4 | |
| Oct. 22 |  Light rain | 16° /12° | 3.3 mm | 3 | |
| Oct. 23 | Overcast | 17° /12° | 0 mm | 4 | |
| Oct. 24 | Sunny | 19° /13° | 0 mm | 4 | |
| Oct. 25 | Overcast | 19° /13° | 0 mm | 4 | |
| Oct. 26 | Cloudy | 18° /12° | 0 mm | 4 | |
| Oct. 27 | Cloudy | 18° /13° | 0 mm | 4 | |
| Oct. 28 | Partly cloudy | 18° /11° | 0 mm | 3.4 | |
| Oct. 29 | Overcast | 18° /12° | 0 mm | 1.9 | |
| Oct. 30 | Sunny | 17° /13° | 0 mm | 3.5 | |
| Oct. 31 | Overcast | 17° /12° | 0 mm | 2.6 | |
| Next | |||||
Important Notice
Our weather forecast for San Mateo County in October 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 October - FAQ
What are the expected maximum and minimum temperatures in San Mateo County during October?
Enjoy moderate daytime temperatures of up to 20° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in San Mateo County during October?
In October, San Mateo County can expect light to moderate rainfall, totaling 29.9 mm across approximately 2 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in San Mateo County during October?
The average wind speed in San Mateo County during October is 15 km/h, suggesting breezy to windy conditions, depending on your activities.
October rainfall patterns in San Mateo County
Explore the daily rainfall trends and prepare for San Mateo Countys October weather 💧
Typically, San Mateo County has 2 rainy days in October with a total of 29.9 mm of rainfall.
UV exposure in San Mateo County during October
Stay informed about UV levels for safe outdoor activities throughout the month of October ☀️
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