Hourly Weather | Today Wednesday, December 24, 2025
Active Weather Warnings
Fullerton, California
4 PM
Rainy Weather
61°
Feels Like 54°
72
Humidity: 94%
Wind: 7 mph
UV Index: 0
5 PM
Rainy Weather
61°
Feels Like 54°
72
Humidity: 91%
Wind: 7 mph
UV Index: 0
6 PM
Cloudy Weather
59°
Feels Like 55°
49
Humidity: 91%
Wind: 7 mph
UV Index: 0
7 PM
Rainy Weather
55°
Feels Like 52°
70
Humidity: 100%
Wind: 6 mph
UV Index: 0
8 PM
Rainy Weather
55°
Feels Like 52°
70
Humidity: 99%
Wind: 6 mph
UV Index: 0
9 PM
Rainy Weather
55°
Feels Like 52°
70
Humidity: 99%
Wind: 6 mph
UV Index: 0
10 PM
Cloudy Weather
55°
Feels Like 54°
40
Humidity: 99%
Wind: 6 mph
UV Index: 0
11 PM
Cloudy Weather
55°
Feels Like 54°
34
Humidity: 99%
Wind: 6 mph
UV Index: 0

Hourly Air Quality Forecast - AQI (US EPA)

4 PM
30 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.24 µg/m³
  • PM10: 3.12 µg/m³
  • O3: 0.032 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.08 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

5 PM
29 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.25 µg/m³
  • PM10: 3.2 µg/m³
  • O3: 0.032 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.08 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

6 PM
29 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.31 µg/m³
  • PM10: 3.51 µg/m³
  • O3: 0.031 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.08 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

7 PM
28 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.38 µg/m³
  • PM10: 3.89 µg/m³
  • O3: 0.031 ppm
  • NO2: 0.2 ppb
  • SO2: 0 ppb
  • CO: 0.08 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

8 PM
28 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.41 µg/m³
  • PM10: 4.18 µg/m³
  • O3: 0.030 ppm
  • NO2: 0.1 ppb
  • SO2: 0 ppb
  • CO: 0.08 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

9 PM
28 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.39 µg/m³
  • PM10: 4.56 µg/m³
  • O3: 0.030 ppm
  • NO2: 0.1 ppb
  • SO2: 0 ppb
  • CO: 0.08 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

10 PM
28 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.38 µg/m³
  • PM10: 5.16 µg/m³
  • O3: 0.031 ppm
  • NO2: 0.1 ppb
  • SO2: 0 ppb
  • CO: 0.09 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

11 PM
30 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 2.38 µg/m³
  • PM10: 5.86 µg/m³
  • O3: 0.032 ppm
  • NO2: 0.1 ppb
  • SO2: 0.1 ppb
  • CO: 0.09 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Weather Alerts and Warnings for Fullerton

Severe Future Possible

Flood Watch

Flood Watch issued December 24 at 1:15PM PST until December 24 at 10:00PM PST by NWS San Diego CA
Dec 24, 1:15 PM Dec 24, 10:00 PM
WHAT: Flooding caused by excessive rainfall continues to be
possible.

WHERE: A portion of Southwest California, including the following
areas, Apple and Lucerne Valleys, Coachella Valley, Orange County
Coastal Areas, Orange County Inland Areas, Riverside County
Mountains, San Bernardino County Mountains, San Bernardino and
Riverside County Valleys-The Inland Empire, San Gorgonio Pass near
Banning and Santa Ana Mountains and Foothills.

WHEN: Until 10 PM PST this evening.

IMPACTS: Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Flooding may occur in poor drainage and urban areas. Mud and
debris flow are possible near and in burn scars, including the
Airport, Bridge and Line burn scars.

ADDITIONAL DETAILS:
- An Atmospheric River will bring widespread moderate to heavy
rain to the region today. The heaviest and most widespread
rain is expected through this evening. Peak rainfall rates of
0.50 to 1 inch per hour are expected. There is a potential
for locally heavier hourly rainfall rates to develop with
convection embedded in the main rain band or in thunderstorms
after the main band passes. Isolated heavy showers could
continue into Thursday but impacts from any additional rain
are expected to be more localized.

Snow levels are expected to remain above 8000 feet during
period of heaviest precipitation bringing a heightened risk
of mud slides, debris flow, and areas of flash flooding in
the San Bernardino county mountains.
- https://www.weather.gov/safety/flood
+ Read More
You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop. Be alert in the mountains for rockslides and rocks in the road.
Updated: Dec 24, 2:59 PM Source: NWS Alert
Moderate Expected Likely

Wind Advisory

Wind Advisory issued December 24 at 1:12PM PST until December 24 at 10:00PM PST by NWS San Diego CA
Dec 24, 1:12 PM Dec 24, 10:00 PM
WHAT: South winds 20 to 30 mph with gusts to 45 mph, locally
higher, expected.

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

WHEN: Until 10 PM PST this evening.

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: Dec 24, 2:59 PM Source: NWS Alert
Minor Expected Likely

Flood Advisory

Flood Advisory issued December 24 at 10:52AM PST until December 24 at 3:51PM PST by NWS San Diego CA
Dec 24, 10:52 AM Dec 24, 3:51 PM
WHAT: Urban and small stream flooding caused by excessive
rainfall is expected.

WHERE: A portion of Southwest California, including the following
counties, Orange, Riverside and San Bernardino.

WHEN: Until 351 PM PST.

IMPACTS: Minor flooding in low-lying and poor drainage areas.
Overflowing poor drainage areas. Ponding of water in urban or
other areas is occurring or is imminent.

ADDITIONAL DETAILS:
- At 1052 AM PST, Doppler radar indicated heavy rain. This will
cause urban and small stream flooding. Between 0.5 and 0.75
inches of rain have fallen.
- Additional rainfall amounts of 1 to 2.5 inches are expected
over the area. This additional rain will result in minor
flooding.
- Some locations that will experience flooding include...
Anaheim, Santa Ana, Riverside, Irvine, Moreno Valley,
Huntington Beach, Garden Grove, Ontario, Corona and Orange.
- https://www.weather.gov/safety/flood
+ Read More
Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles.
Updated: Dec 24, 2:59 PM Source: NWS Alert