Today | Weather | Thursday, December 4, 2025

Weather in Fontana, California

01:30 AM
Now
Night
48° F
Feels Like 45°
Precipitation 0 %
Wind 7 mph
Humidity 36 %
Today
Cloudy Weather
Day 70°
Night 45°
Precipitation 0 %
Wind 9 mph
UV Index (0 - 11+) 3

Fontana Weather Forecast Updated

13 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (December 4, 2024)
Night

Day

66°

Night

43°

Wind

4 mph

Precipitation

0 %

Air Quality in Fontana

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

Pollutant Concentrations:

PM2.5 27.05 µg/m³
PM10 38.3 µg/m³
O3 0.035 ppm
NO2 11.7 ppb
SO2 2.5 ppb
CO 0.27 ppm
NH3 0.57 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)
PM2.527.05 µg/m³
PM1038.3 µg/m³
O369.12 µg/m³
NO222.1 µg/m³
SO26.55 µg/m³
CO303.83 µg/m³
NH30.57 µg/m³
NO0 µg/m³