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Hourly Weather | Today › Wednesday, August 5, 2026
Active Weather Warnings
Ontario, California
5 AM
Cloudy Night
66°
Feels Like 66°
20
Humidity: 81%
UV Index: 0
Wind: 0 mph
6 AM
Cloudy Night
64°
Feels Like 66°
20
Humidity: 81%
UV Index: 0
Wind: 0 mph
7 AM
Cloudy Weather
66°
Feels Like 70°
13
Humidity: 83%
UV Index: 1
Wind: 0 mph
8 AM
Cloudy Weather
70°
Feels Like 72°
0
Humidity: 75%
UV Index: 2
Wind: 4 mph
9 AM
Cloudy Weather
73°
Feels Like 79°
0
Humidity: 66%
UV Index: 3
Wind: 5 mph
10 AM
Cloudy Weather
79°
Feels Like 84°
0
Humidity: 58%
UV Index: 5
Wind: 5 mph
11 AM
Sunny Weather
81°
Feels Like 90°
0
Humidity: 52%
UV Index: 7
Wind: 6 mph
12 PM
Sunny Weather
84°
Feels Like 93°
0
Humidity: 45%
UV Index: 10
Wind: 7 mph
1 PM
Sunny Weather
88°
Feels Like 95°
0
Humidity: 40%
UV Index: 11
Wind: 8 mph
2 PM
Cloudy Weather
90°
Feels Like 97°
0
Humidity: 36%
UV Index: 10
Wind: 9 mph
3 PM
Cloudy Weather
91°
Feels Like 95°
0
Humidity: 34%
UV Index: 7
Wind: 10 mph
4 PM
Cloudy Weather
91°
Feels Like 91°
0
Humidity: 35%
UV Index: 5
Wind: 10 mph
5 PM
Cloudy Weather
90°
Feels Like 90°
0
Humidity: 36%
UV Index: 3
Wind: 12 mph
6 PM
Cloudy Weather
88°
Feels Like 88°
0
Humidity: 38%
UV Index: 2
Wind: 10 mph
7 PM
Cloudy Weather
84°
Feels Like 82°
0
Humidity: 44%
UV Index: 1
Wind: 9 mph
8 PM
Cloudy Night
81°
Feels Like 79°
0
Humidity: 51%
UV Index: 0
Wind: 9 mph
9 PM
Cloudy Night
79°
Feels Like 75°
0
Humidity: 56%
UV Index: 0
Wind: 7 mph
10 PM
Night
75°
Feels Like 73°
0
Humidity: 62%
UV Index: 0
Wind: 6 mph
11 PM
Night
73°
Feels Like 72°
0
Humidity: 68%
UV Index: 0
Wind: 5 mph

Hourly Air Quality Forecast - AQI (US EPA)

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

Pollutant Concentrations:

  • PM2.5: 9.49 µg/m³
  • PM10: 29.33 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

6 AM
40 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 9.48 µg/m³
  • PM10: 28.86 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

7 AM
40 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 9.51 µg/m³
  • PM10: 28.64 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.7 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

8 AM
40 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 9.61 µg/m³
  • PM10: 28.73 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.7 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

9 AM
41 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 9.81 µg/m³
  • PM10: 28.87 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 10.19 µg/m³
  • PM10: 29.35 µg/m³
  • O3: 0.037 ppm
  • NO2: 0.6 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 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: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 10.8 µg/m³
  • PM10: 30.18 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.5 ppb
  • SO2: 0.4 ppb
  • CO: 0.07 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: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 11.34 µg/m³
  • PM10: 30.94 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.3 ppb
  • SO2: 0.3 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

1 PM
48 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 11.6 µg/m³
  • PM10: 31.39 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.2 ppb
  • SO2: 0.3 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

2 PM
49 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 11.75 µg/m³
  • PM10: 31.75 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.1 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

3 PM
50 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 11.91 µg/m³
  • PM10: 32.13 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.1 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

4 PM
50 AQI
Good air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 12.13 µg/m³
  • PM10: 32.49 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.1 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 12.39 µg/m³
  • PM10: 32.72 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.1 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

6 PM
51 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 12.59 µg/m³
  • PM10: 32.44 µg/m³
  • O3: 0.041 ppm
  • NO2: 0.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 12.83 µg/m³
  • PM10: 32.35 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 13.12 µg/m³
  • PM10: 32.46 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 13.41 µg/m³
  • PM10: 32.59 µg/m³
  • O3: 0.040 ppm
  • NO2: 0.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

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

Pollutant Concentrations:

  • PM2.5: 13.89 µg/m³
  • PM10: 33.2 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

11 PM
56 AQI
Moderate air quality Dominant pollutant: PM2.5
Details

Pollutant Concentrations:

  • PM2.5: 14.64 µg/m³
  • PM10: 34.37 µg/m³
  • O3: 0.039 ppm
  • NO2: 0.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.07 ppm

Health Recommendations:

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

Current Real-Time Air Quality Report

Weather Alerts and Warnings for Ontario

Moderate Expected Likely

Heat Advisory

Heat Advisory issued August 4 at 9:35PM PDT until August 8 at 8:00PM PDT by NWS San Diego CA
Aug 4, 9:35 PM → Aug 8, 8:00 PM
WHAT: High temperatures in the upper 90s to 105 expected.

WHERE: San Bernardino and Riverside County Valleys-The Inland
Empire.

WHEN: Until 8 PM PDT Saturday.

IMPACTS: Hot temperatures may cause heat illnesses.
+ Read More
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.
Updated: Aug 5, 3:32 AM Source: NWS Alert

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