Today | Weather | Tuesday, November 11, 2025

Weather in San Mateo, California

02:11 AM
Now
Cloudy Night
54° F
Feels Like 54°
Precipitation 0 %
Wind 4 mph
Humidity 93 %
Today
Cloudy Weather
Day 70°
Night 57°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 3

San Mateo Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (November 11, 2024)
Cloudy Night

Day

61°

Night

46°

Wind

6 mph

Precipitation

7 %

Air Quality in San Mateo

NOW
49 AQI
Good air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 11.7 µg/m³
PM10 18.32 µg/m³
O3 0.022 ppm
NO2 2 ppb
SO2 0.3 ppb
CO 0.13 ppm
NH3 0 µg/m³
NO 0 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.511.7 µg/m³
PM1018.32 µg/m³
O343.47 µg/m³
NO23.81 µg/m³
SO20.76 µg/m³
CO148.32 µg/m³
NH30 µg/m³
NO0 µg/m³