Today | Weather | Tuesday, January 13, 2026

Weather in San Mateo, California

01:24 PM
Now
Sunny Weather
61° F
Feels Like 63°
Precipitation 0 %
Wind 7 mph
UV Index (0 - 11+) 2
Humidity 57 %
Today
Sunny Weather
Day 64°
Night 41°
Precipitation 0 %
Wind 5 mph
UV Index (0 - 11+) 3

San Mateo Weather Forecast Updated

1 minute ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (January 13, 2025)
Sunny Weather

Day

63°

Night

39°

Wind

14 mph

UV Index

3

Precipitation

0 %

Air Quality in San Mateo

NOW
96 AQI
Moderate air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 33.53 µg/m³
PM10 41.49 µg/m³
O3 0.039 ppm
NO2 9.6 ppb
SO2 1.1 ppb
CO 0.32 ppm
NH3 0.31 µg/m³
NO 4.67 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 acceptable; however, for some pollutants, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

Show raw pollutant concentrations (µg/m³)
PM2.533.53 µg/m³
PM1041.49 µg/m³
O375.76 µg/m³
NO218.1 µg/m³
SO22.93 µg/m³
CO367.67 µg/m³
NH30.31 µg/m³
NO4.67 µg/m³