Today | Weather | Wednesday, February 4, 2026
Active Weather Warnings

Weather in Fullerton, California

02:50 PM
Now
Sunny Weather
90° F
Feels Like 86°
Precipitation 0 %
Wind 21 mph
UV Index (0 - 11+) 2
Humidity 12 %
Today
Sunny Weather
Day 91°
Night 55°
Precipitation 0 %
Wind 14 mph
UV Index (0 - 11+) 4

Fullerton Weather Forecast Updated

Weather Forecast History
Last Year's Weather on This Day (February 4, 2025)
Cloudy Weather

Day

64°

Night

54°

Wind

4 mph

UV Index

2

Precipitation

40 %

Air Quality in Fullerton

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

Pollutant Concentrations:

PM2.5 48.25 µg/m³
PM10 60.12 µg/m³
O3 0.072 ppm
NO2 17.2 ppb
SO2 1.2 ppb
CO 0.44 ppm
NH3 0.78 µg/m³
NO 4.34 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)
PM2.548.25 µg/m³
PM1060.12 µg/m³
O3141.3 µg/m³
NO232.38 µg/m³
SO23.09 µg/m³
CO504.61 µg/m³
NH30.78 µg/m³
NO4.34 µg/m³

Weather Alerts and Warnings for Fullerton

Moderate Expected Likely

Wind Advisory

Wind Advisory issued February 4 at 2:45AM PST until February 5 at 12:00PM PST by NWS San Diego CA
Feb 4, 4:00 AM Feb 5, 12:00 PM
WHAT: Northeast winds 20 to 30 mph with gusts up to 45 mph
expected. Isolated gusts to 55 mph.

WHERE: Orange County Inland Areas, Riverside County Mountains,
San Bernardino County Mountains, San Bernardino and Riverside
County Valleys-The Inland Empire, San Diego County Mountains, San
Diego County Valleys, San Gorgonio Pass near Banning, and Santa
Ana Mountains and Foothills.

WHEN: Until noon PST Thursday.

IMPACTS: Gusty winds will blow around unsecured objects. Tree
limbs could be blown down and a few power outages may result.
+ Read More
Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution.
Updated: Feb 4, 11:43 AM Source: NWS Alert

Air Quality Alert

Air Quality Alert issued February 3 at 4:51PM PST by NWS San Diego CA
Feb 3, 4:51 PM Feb 4, 11:00 PM
WHAT: The South Coast AQMD has issued an air quality alert due to
harmful levels of particle pollution from windblown dust. Visit
https://www.aqmd.gov/alertinfo to check current and forecasted air
quality levels.

WHERE: In parts of the Inland Empire, Orange County, and South
Coastal LA County. Levels of particle pollution can vary by time
and location depending on emissions and local weather conditions.

WHEN: Until 11 PM Wednesday.

IMPACTS: Particle pollution can get deep into the lungs and cause
serious health problems such as asthma attacks, heart and lung
disease symptoms, and increased risk of lung infections. Everyone
can be affected, but sensitive groups such as people with lung or
heart disease, older adults, people who are pregnant, children, and
those who spend a lot of time outdoors are at greater risk.
+ Read More
To protect your health, check air quality levels and act as needed: * When Air Quality Index (AQI) levels are "Unhealthy for Sensitive Groups" (orange), sensitive groups as specified above should limit extended or intense outdoor activity. * When AQI is "Unhealthy" (red), everyone may experience health impacts. Sensitive groups should avoid extended time outdoors. * When AQI is "Very Unhealthy" (purple), sensitive groups should avoid all outdoor physical activity. Everyone else should avoid extended or intense outdoor activity. * When AQI is "Hazardous" (maroon), everyone should avoid all outdoor physical activity. * ADDITIONAL DETAILS... To help keep indoor air clean when air quality is poor: * Keep windows and doors closed * Run your air conditioner and/or an air purifier * Do not use whole house fans or swamp coolers that bring in outside air if you have other methods to stay cool * Avoid other sources of pollution such as fireplaces, candles, incense, grilling, and gasoline-powered lawn and garden equipment To help minimize outdoor particle pollution levels: * Carpool, telecommute, reduce trips, or take public transportation * Slow down if driving on dirt roads * Stabilize loose soils
Updated: Feb 4, 11:43 AM Source: NWS Alert