Hourly Weather Forecast for Joliet, Illinois

Hourly Weather | Today › Saturday, September 19, 2026

Active Weather Warnings

Flood Watch

Joliet, Illinois

5 AM

66°

Feels Like 61°

Humidity: 93%

UV Index: 0

Wind: 7 mph

6 AM

64°

Feels Like 64°

Humidity: 96%

UV Index: 0

Wind: 7 mph

7 AM

66°

Feels Like 64°

Humidity: 95%

UV Index: 0

Wind: 7 mph

8 AM

64°

Feels Like 61°

Humidity: 100%

UV Index: 0

Wind: 6 mph

9 AM

66°

Feels Like 64°

Humidity: 100%

UV Index: 0

Wind: 6 mph

10 AM

70°

Feels Like 72°

Humidity: 98%

UV Index: 1

Wind: 6 mph

11 AM

72°

Feels Like 72°

Humidity: 94%

UV Index: 1

Wind: 7 mph

12 PM

75°

Feels Like 81°

Humidity: 87%

UV Index: 1

Wind: 7 mph

1 PM

77°

Feels Like 82°

Humidity: 82%

UV Index: 1

Wind: 7 mph

2 PM

79°

Feels Like 84°

Humidity: 79%

UV Index: 1

Wind: 7 mph

3 PM

82°

Feels Like 88°

Humidity: 71%

UV Index: 1

Wind: 7 mph

4 PM

81°

Feels Like 82°

Humidity: 84%

UV Index: 1

Wind: 7 mph

5 PM

79°

Feels Like 81°

Humidity: 80%

UV Index: 0

Wind: 6 mph

6 PM

79°

Feels Like 81°

Humidity: 81%

UV Index: 0

Wind: 6 mph

7 PM

79°

Feels Like 84°

Humidity: 83%

UV Index: 0

Wind: 5 mph

8 PM

75°

Feels Like 82°

Humidity: 88%

UV Index: 0

Wind: 5 mph

9 PM

75°

Feels Like 81°

Humidity: 91%

UV Index: 0

Wind: 6 mph

10 PM

73°

Feels Like 79°

Humidity: 92%

UV Index: 0

Wind: 6 mph

11 PM

73°

Feels Like 73°

Humidity: 94%

UV Index: 0

Wind: 5 mph

Hourly Air Quality Forecast - AQI (US EPA)

5 AM

44 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 10.51 µg/m³
PM₁₀: 10.98 µg/m³
O₃: 0.027 ppm
NO₂: 1.6 ppb
SO₂: 0.3 ppb
CO: 0.18 ppm

Health Recommendations:

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

6 AM

45 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 10.84 µg/m³
PM₁₀: 11.24 µg/m³
O₃: 0.027 ppm
NO₂: 1.5 ppb
SO₂: 0.3 ppb
CO: 0.17 ppm

Health Recommendations:

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

7 AM

46 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 11.1 µg/m³
PM₁₀: 11.45 µg/m³
O₃: 0.027 ppm
NO₂: 1.5 ppb
SO₂: 0.3 ppb
CO: 0.17 ppm

Health Recommendations:

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

8 AM

46 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 11.11 µg/m³
PM₁₀: 11.45 µg/m³
O₃: 0.027 ppm
NO₂: 1.7 ppb
SO₂: 0.3 ppb
CO: 0.16 ppm

Health Recommendations:

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

9 AM

45 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 10.83 µg/m³
PM₁₀: 11.16 µg/m³
O₃: 0.028 ppm
NO₂: 1.7 ppb
SO₂: 0.4 ppb
CO: 0.15 ppm

Health Recommendations:

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

10 AM

43 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 10.32 µg/m³
PM₁₀: 10.67 µg/m³
O₃: 0.031 ppm
NO₂: 1.5 ppb
SO₂: 0.5 ppb
CO: 0.14 ppm

Health Recommendations:

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

11 AM

41 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 9.85 µg/m³
PM₁₀: 10.25 µg/m³
O₃: 0.035 ppm
NO₂: 1.4 ppb
SO₂: 0.7 ppb
CO: 0.14 ppm

Health Recommendations:

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

12 PM

41 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 9.78 µg/m³
PM₁₀: 10.24 µg/m³
O₃: 0.037 ppm
NO₂: 1.4 ppb
SO₂: 0.8 ppb
CO: 0.13 ppm

Health Recommendations:

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

1 PM

42 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 10.06 µg/m³
PM₁₀: 10.53 µg/m³
O₃: 0.039 ppm
NO₂: 1.3 ppb
SO₂: 0.7 ppb
CO: 0.13 ppm

Health Recommendations:

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

2 PM

42 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 10.19 µg/m³
PM₁₀: 10.67 µg/m³
O₃: 0.040 ppm
NO₂: 1.4 ppb
SO₂: 0.7 ppb
CO: 0.13 ppm

Health Recommendations:

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

3 PM

41 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 9.77 µg/m³
PM₁₀: 10.25 µg/m³
O₃: 0.040 ppm
NO₂: 1.4 ppb
SO₂: 0.6 ppb
CO: 0.13 ppm

Health Recommendations:

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

4 PM

37 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 8.88 µg/m³
PM₁₀: 9.35 µg/m³
O₃: 0.040 ppm
NO₂: 1.5 ppb
SO₂: 0.5 ppb
CO: 0.13 ppm

Health Recommendations:

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

5 PM

37 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 7.69 µg/m³
PM₁₀: 8.14 µg/m³
O₃: 0.040 ppm
NO₂: 1.6 ppb
SO₂: 0.5 ppb
CO: 0.13 ppm

Health Recommendations:

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

6 PM

35 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 6.68 µg/m³
PM₁₀: 7.11 µg/m³
O₃: 0.038 ppm
NO₂: 2.2 ppb
SO₂: 0.4 ppb
CO: 0.13 ppm

Health Recommendations:

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

7 PM

33 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 5.74 µg/m³
PM₁₀: 6.16 µg/m³
O₃: 0.036 ppm
NO₂: 2.6 ppb
SO₂: 0.3 ppb
CO: 0.13 ppm

Health Recommendations:

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

8 PM

29 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 5.31 µg/m³
PM₁₀: 5.73 µg/m³
O₃: 0.032 ppm
NO₂: 3.1 ppb
SO₂: 0.3 ppb
CO: 0.13 ppm

Health Recommendations:

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

9 PM

25 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 5.25 µg/m³
PM₁₀: 5.71 µg/m³
O₃: 0.027 ppm
NO₂: 3.7 ppb
SO₂: 0.2 ppb
CO: 0.14 ppm

Health Recommendations:

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

10 PM

23 AQI

Good air quality Dominant pollutant: O₃

Details

Pollutant Concentrations:

PM_2.5: 5.27 µg/m³
PM₁₀: 5.77 µg/m³
O₃: 0.024 ppm
NO₂: 4.1 ppb
SO₂: 0.2 ppb
CO: 0.15 ppm

Health Recommendations:

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

11 PM

22 AQI

Good air quality Dominant pollutant: PM_2.5

Details

Pollutant Concentrations:

PM_2.5: 5.22 µg/m³
PM₁₀: 5.71 µg/m³
O₃: 0.022 ppm
NO₂: 4.4 ppb
SO₂: 0.3 ppb
CO: 0.15 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 Joliet

Severe Future Possible

Flood Watch

Flood Watch issued September 19 at 3:39AM CDT until September 19 at 1:00PM CDT by NWS Chicago IL

Sep 19, 4:00 AM → Sep 19, 1:00 PM

WHAT: Flash flooding caused by excessive rainfall continues to be
possible.

WHERE: Portions of Illinois, including the following areas,
Central Cook, De Kalb, DuPage, Kane, Kendall, Lake IL, Lee,
Northern Cook, Northern Will and Southern Cook and northwest
Indiana, including the following areas, Lake IN and Porter.

WHEN: Until 1 PM CDT this afternoon.

IMPACTS: Creeks and streams may rise out of their banks. Flooding
may occur in poor drainage and urban areas. Roads and streets may
be flooded.

ADDITIONAL DETAILS:
- Showers and thunderstorms will produce heavy rain this morning
which may cause localized flash flooding. Additional showers and
thunderstorms may produce heavy rain and localized flash flooding
tonight when another flood watch for flash flooding may be
needed.
- http://www.weather.gov/safety/flood

+ Read More

A Flood Watch for flash flooding means rapid-onset flooding is possible, but not yet certain, based upon the latest forecasts. Flash flooding is a dangerous situation. Persons with interests along area rivers, creeks, and other waterways should monitor the latest forecasts and be prepared to take action should flooding develop.

Updated: Sep 19, 3:51 AM Source: NWS Alert

Hourly Air Quality Forecast - AQI (US EPA)

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Weather Alerts and Warnings for Joliet

Flood Watch

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