Today | Weather | Tuesday, January 13, 2026

Weather in Fullerton, California

12:26 PM
Now
Sunny Weather
73° F
Feels Like 77°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 3
Humidity 25 %
Today
Sunny Weather
Day 79°
Night 46°
Precipitation 0 %
Wind 5 mph
UV Index (0 - 11+) 3

Fullerton Weather Forecast Updated

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

Day

68°

Night

43°

Wind

12 mph

UV Index

3

Precipitation

0 %

Air Quality in Fullerton

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

Pollutant Concentrations:

PM2.5 35.24 µg/m³
PM10 49.67 µg/m³
O3 0.042 ppm
NO2 16.8 ppb
SO2 1.3 ppb
CO 0.43 ppm
NH3 0.6 µg/m³
NO 8.32 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)
PM2.535.24 µg/m³
PM1049.67 µg/m³
O383.14 µg/m³
NO231.57 µg/m³
SO23.32 µg/m³
CO495.59 µg/m³
NH30.6 µg/m³
NO8.32 µg/m³