Hourly Weather | Today Wednesday, May 20, 2026
Active Weather Warnings
Mission Viejo, California
5 PM
Cloudy Weather
81°
Feels Like 82°
0
Humidity: 26%
UV Index: 3
Wind: 8 mph
6 PM
Cloudy Weather
79°
Feels Like 79°
0
Humidity: 30%
UV Index: 2
Wind: 8 mph
7 PM
Cloudy Weather
75°
Feels Like 75°
0
Humidity: 36%
UV Index: 1
Wind: 6 mph
8 PM
Cloudy Night
72°
Feels Like 70°
0
Humidity: 41%
UV Index: 0
Wind: 6 mph
9 PM
Cloudy Night
70°
Feels Like 66°
0
Humidity: 49%
UV Index: 0
Wind: 6 mph
10 PM
Cloudy Night
66°
Feels Like 64°
0
Humidity: 58%
UV Index: 0
Wind: 6 mph
11 PM
Cloudy Night
63°
Feels Like 63°
0
Humidity: 68%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 9.49 µg/m³
  • PM10: 23.85 µg/m³
  • O3: 0.053 ppm
  • NO2: 0.2 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 9.52 µg/m³
  • PM10: 24.65 µg/m³
  • O3: 0.053 ppm
  • NO2: 0.2 ppb
  • SO2: 0.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 9.65 µg/m³
  • PM10: 25.38 µg/m³
  • O3: 0.053 ppm
  • NO2: 0.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 9.74 µg/m³
  • PM10: 25.86 µg/m³
  • O3: 0.052 ppm
  • NO2: 0.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 9.7 µg/m³
  • PM10: 25.69 µg/m³
  • O3: 0.051 ppm
  • NO2: 0.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 9.66 µg/m³
  • PM10: 25.42 µg/m³
  • O3: 0.050 ppm
  • NO2: 0.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 9.57 µg/m³
  • PM10: 25.06 µg/m³
  • O3: 0.048 ppm
  • NO2: 0.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.10 ppm

Health Recommendations:

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

Weather Alerts and Warnings for Mission Viejo

Air Quality Alert

Air Quality Alert issued May 19 at 9:42PM PDT by NWS San Diego CA
May 19, 9:42 PM May 20, 9:45 PM
WHAT: The South Coast AQMD has issued an air quality alert due to
increased fine particle pollution from wildfire smoke. Visit
https://www.aqmd.gov/alertinfo to check current and forecasted air
quality levels.

WHERE: most of LA County and all of Orange County. Levels of
particle pollution can vary by time and location depending on fire
activity and local weather conditions.

WHEN: until Tuesday evening.

IMPACTS: Particles in wildfire smoke can get deep into the lungs
and cause serious health problems such as heart attacks, strokes,
asthma attacks, and difficulty breathing. Everyone can be affected,
but 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, if you smell or see smoke: * Remain indoors with windows and doors closed * Avoid intense outdoor physical activity * Run your air conditioner and/or an air purifier * If you must be outdoors, keep the time brief and wear a well- fitting N-95 mask * 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
Updated: May 20, 3:18 PM Source: NWS Alert