Today | Weather | Sunday, January 18, 2026

Weather in San Jose, California

10:48 PM
Now
Cloudy Night
52° F
Feels Like 52°
Precipitation 0 %
Wind 5 mph
Humidity 77 %
Today
Cloudy Night
Day 68°
Night 43°
Precipitation 0 %
Wind 4 mph

San Jose Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (January 18, 2025)
Cloudy Weather

Day

63°

Night

37°

Wind

4 mph

UV Index

3

Precipitation

0 %

Air Quality in San Jose

NOW
102 AQI
Unhealthy air quality for sensitive groups Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 36.26 µg/m³
PM10 45.29 µg/m³
O3 0.033 ppm
NO2 7.1 ppb
SO2 0.6 ppb
CO 0.29 ppm
NH3 0.24 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:

Members of sensitive groups may experience health effects. The general public is not likely to be affected.

Show raw pollutant concentrations (µg/m³)
PM2.536.26 µg/m³
PM1045.29 µg/m³
O364.25 µg/m³
NO213.38 µg/m³
SO21.56 µg/m³
CO331.11 µg/m³
NH30.24 µg/m³
NO0 µg/m³