Today | Weather | Sunday, January 18, 2026

Weather in San Jose, California

11:52 PM
Now
Cloudy Night
48° F
Feels Like 48°
Precipitation 0 %
Wind 5 mph
Humidity 75 %
Today
Sunny Weather
Day 70°
Night 43°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 3

San Jose Weather Forecast Updated

37 minutes ago
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
97 AQI
Moderate air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 33.97 µg/m³
PM10 43.35 µg/m³
O3 0.030 ppm
NO2 7.1 ppb
SO2 0.6 ppb
CO 0.28 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:

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)
PM2.533.97 µg/m³
PM1043.35 µg/m³
O358.9 µg/m³
NO213.4 µg/m³
SO21.47 µg/m³
CO323.68 µg/m³
NH30.24 µg/m³
NO0 µg/m³