Today | Weather | Wednesday, October 1, 2025

Weather in San Mateo, California

10:05 AM

Now

66° F

Feels Like 63°

Precipitation 54 %

Wind 8 mph

UV Index (0 - 11+) 7

Humidity 72 %

Today

Day 73°

Night 63°

Precipitation 84 %

Wind 8 mph

UV Index (0 - 11+) 10

Warning: High UV Index Today: 10

High risk of harm from unprotected sun exposure. Take precautions: wear a hat, sunglasses, and apply sunscreen regularly if you’ll be outdoors for extended periods.

San Mateo Weather Forecast Updated

50 minutes ago

Last updated on October 01, 2025 9:14 AM

Air quality in San Mateo

NOW

31 AQI

Good air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 6.47 µg/m³

PM10 8.03 µg/m³

O₃ 26.39 ppb

NO₂ 7.04 ppb

SO₂ 1.05 ppb

CO 144.67 ppb

PM_2.5 – Fine particles <2.5μm

PM₁₀ – Inhalable particles <10μm

O₃ – Ozone

NO₂ – Nitrogen dioxide

SO₂ – Sulfur dioxide

CO – Carbon monoxide

Health Recommendations:

With this level of air quality, you have no limitations. Enjoy the outdoors

View Hourly Air Quality Forecast