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Today Hourly 7 days 30 days Air Quality
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Hourly Weather | Today › Thursday, December 4, 2025
Active Weather Warnings
Costa Mesa, California
3 AM
Night
52°
Feels Like 39°
0
Humidity: 48%
Wind: 22 mph
UV Index: 0
4 AM
Night
50°
Feels Like 39°
0
Humidity: 53%
Wind: 22 mph
UV Index: 0
5 AM
Night
48°
Feels Like 39°
0
Humidity: 55%
Wind: 18 mph
UV Index: 0
6 AM
Night
48°
Feels Like 39°
0
Humidity: 57%
Wind: 15 mph
UV Index: 0
7 AM
Cloudy Weather
52°
Feels Like 43°
0
Humidity: 53%
Wind: 15 mph
UV Index: 0
8 AM
Cloudy Weather
54°
Feels Like 46°
0
Humidity: 50%
Wind: 14 mph
UV Index: 1
9 AM
Cloudy Weather
61°
Feels Like 57°
0
Humidity: 41%
Wind: 13 mph
UV Index: 2
10 AM
Cloudy Weather
64°
Feels Like 63°
0
Humidity: 36%
Wind: 12 mph
UV Index: 2
11 AM
Cloudy Weather
66°
Feels Like 66°
0
Humidity: 32%
Wind: 12 mph
UV Index: 3
12 PM
Cloudy Weather
70°
Feels Like 70°
0
Humidity: 29%
Wind: 13 mph
UV Index: 3
1 PM
Cloudy Weather
72°
Feels Like 73°
0
Humidity: 27%
Wind: 6 mph
UV Index: 3
2 PM
Sunny Weather
73°
Feels Like 73°
0
Humidity: 26%
Wind: 6 mph
UV Index: 2
3 PM
Sunny Weather
72°
Feels Like 72°
0
Humidity: 29%
Wind: 6 mph
UV Index: 2
4 PM
Cloudy Weather
70°
Feels Like 68°
0
Humidity: 34%
Wind: 6 mph
UV Index: 1
5 PM
Cloudy Night
64°
Feels Like 63°
0
Humidity: 40%
Wind: 4 mph
UV Index: 0
6 PM
Cloudy Night
63°
Feels Like 63°
0
Humidity: 44%
Wind: 2 mph
UV Index: 0
7 PM
Cloudy Night
59°
Feels Like 61°
0
Humidity: 49%
Wind: 4 mph
UV Index: 0
8 PM
Night
57°
Feels Like 57°
0
Humidity: 54%
Wind: 4 mph
UV Index: 0
9 PM
Night
54°
Feels Like 54°
0
Humidity: 58%
Wind: 4 mph
UV Index: 0
10 PM
Night
54°
Feels Like 54°
0
Humidity: 61%
Wind: 4 mph
UV Index: 0
11 PM
Night
52°
Feels Like 52°
0
Humidity: 62%
Wind: 4 mph
UV Index: 0

Hourly Air Quality Forecast - AQI (US EPA)

3 AM
74 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 23.45 µg/m³
  • PM10: 33.18 µg/m³
  • O3: 0.046 ppm
  • NO2: 4.7 ppb
  • SO2: 1.4 ppb
  • CO: 0.21 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

4 AM
74 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 23.09 µg/m³
  • PM10: 33.05 µg/m³
  • O3: 0.045 ppm
  • NO2: 4.8 ppb
  • SO2: 1.4 ppb
  • CO: 0.22 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

5 AM
70 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 21.58 µg/m³
  • PM10: 31.63 µg/m³
  • O3: 0.043 ppm
  • NO2: 4.6 ppb
  • SO2: 1.4 ppb
  • CO: 0.22 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

6 AM
67 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 20.03 µg/m³
  • PM10: 30.28 µg/m³
  • O3: 0.042 ppm
  • NO2: 4.3 ppb
  • SO2: 1.3 ppb
  • CO: 0.22 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

7 AM
63 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 17.98 µg/m³
  • PM10: 28.56 µg/m³
  • O3: 0.041 ppm
  • NO2: 4 ppb
  • SO2: 1.2 ppb
  • CO: 0.21 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

8 AM
57 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 15.23 µg/m³
  • PM10: 26.17 µg/m³
  • O3: 0.041 ppm
  • NO2: 3.9 ppb
  • SO2: 1 ppb
  • CO: 0.20 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

9 AM
51 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 12.61 µg/m³
  • PM10: 23.72 µg/m³
  • O3: 0.043 ppm
  • NO2: 3.3 ppb
  • SO2: 0.9 ppb
  • CO: 0.19 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

10 AM
46 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 10.98 µg/m³
  • PM10: 22.05 µg/m³
  • O3: 0.046 ppm
  • NO2: 2.9 ppb
  • SO2: 0.8 ppb
  • CO: 0.18 ppm

Health Recommendations:

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

11 AM
45 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 10.14 µg/m³
  • PM10: 20.95 µg/m³
  • O3: 0.048 ppm
  • NO2: 2.8 ppb
  • SO2: 0.8 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

12 PM
47 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 10.08 µg/m³
  • PM10: 20.54 µg/m³
  • O3: 0.051 ppm
  • NO2: 2.8 ppb
  • SO2: 0.8 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

1 PM
49 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 10.47 µg/m³
  • PM10: 20.58 µg/m³
  • O3: 0.053 ppm
  • NO2: 2.9 ppb
  • SO2: 0.9 ppb
  • CO: 0.17 ppm

Health Recommendations:

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

2 PM
53 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 11.42 µg/m³
  • PM10: 21.28 µg/m³
  • O3: 0.055 ppm
  • NO2: 3.1 ppb
  • SO2: 1 ppb
  • CO: 0.17 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

3 PM
57 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 12.36 µg/m³
  • PM10: 22.09 µg/m³
  • O3: 0.056 ppm
  • NO2: 3.5 ppb
  • SO2: 1 ppb
  • CO: 0.17 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

4 PM
58 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 12.93 µg/m³
  • PM10: 22.55 µg/m³
  • O3: 0.056 ppm
  • NO2: 4 ppb
  • SO2: 1 ppb
  • CO: 0.17 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

5 PM
56 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 13.25 µg/m³
  • PM10: 22.75 µg/m³
  • O3: 0.056 ppm
  • NO2: 4.2 ppb
  • SO2: 1 ppb
  • CO: 0.17 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

6 PM
55 AQI
Moderate air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 13.75 µg/m³
  • PM10: 23.27 µg/m³
  • O3: 0.056 ppm
  • NO2: 3.6 ppb
  • SO2: 1 ppb
  • CO: 0.17 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

7 PM
55 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 14.26 µg/m³
  • PM10: 23.91 µg/m³
  • O3: 0.055 ppm
  • NO2: 3 ppb
  • SO2: 1 ppb
  • CO: 0.18 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

8 PM
55 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 14.42 µg/m³
  • PM10: 24.14 µg/m³
  • O3: 0.055 ppm
  • NO2: 2.4 ppb
  • SO2: 1 ppb
  • CO: 0.18 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

9 PM
55 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 14.26 µg/m³
  • PM10: 23.8 µg/m³
  • O3: 0.054 ppm
  • NO2: 2 ppb
  • SO2: 0.9 ppb
  • CO: 0.18 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

10 PM
53 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 13.19 µg/m³
  • PM10: 22.07 µg/m³
  • O3: 0.053 ppm
  • NO2: 1.7 ppb
  • SO2: 0.8 ppb
  • CO: 0.17 ppm

Health Recommendations:

Air quality is acceptable; some pollutants may pose a risk for a small number of unusually sensitive people.

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

Pollutant Concentrations:

  • PM2.5: 11.16 µg/m³
  • PM10: 18.76 µg/m³
  • O3: 0.053 ppm
  • NO2: 1.2 ppb
  • SO2: 0.7 ppb
  • CO: 0.16 ppm

Health Recommendations:

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

Current Real-Time Air Quality Report

Weather Alerts and Warnings for Costa Mesa

Moderate Expected Likely

Beach Hazards Statement

Beach Hazards Statement issued December 3 at 9:53PM PST until December 5 at 10:00AM PST by NWS San Diego CA
Dec 3, 9:53 PM → Dec 5, 10:00 AM
WHAT: Very high astronomical tides during the mornings combined
with elevated surf up to 5 to 6 feet, primarily at west-facing
beaches today, will result in minor tidal overflow and local
beach flooding.

WHERE: San Diego County Coastal Areas and Orange County
Coastal Areas.

WHEN: Through Friday morning.

IMPACTS: Minor tidal overflow, beach flooding, and coastal
erosion most likely during times of high tides. Hazardous
swimming conditions.

ADDITIONAL DETAILS: Predicted high tides at La Jolla: 7.1
feet at 734 AM Thursday, and 7.1 feet at 818 AM Friday.
+ Read More
Remain out of the water to avoid hazardous swimming conditions.
Updated: Dec 4, 12:46 AM Source: NWS Alert