Today | Weather | Sunday, April 26, 2026

Weather in Fullerton, California

02:13 PM
Now
Cloudy Weather
70° F
Feels Like 73°
Precipitation 20 %
Wind 13 mph
UV Index (0 - 11+) 9
Humidity 37 %
Today
Partly Sunny with Showers
Day 70°
Night 52°
Precipitation 49 %
Wind 10 mph
UV Index (0 - 11+) 7

Fullerton Weather Forecast Updated

16 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (April 26, 2025)
Stormy Weather

Day

63°

Night

50°

Wind

11 mph

UV Index

5

Precipitation

97 %

Air Quality in Fullerton

NOW
53 AQI
Moderate air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 0.55 µg/m³
PM10 1.52 µg/m³
O3 0.055 ppm
NO2 0.1 ppb
SO2 0.1 ppb
CO 0.11 ppm
NH3 0 µg/m³
NO 0.02 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)
PM2.50.55 µg/m³
PM101.52 µg/m³
O3107.61 µg/m³
NO20.16 µg/m³
SO20.3 µg/m³
CO120.55 µg/m³
NH30 µg/m³
NO0.02 µg/m³