Hazard Report Provided By forecast.weather.gov

ILZ003>006-008-010>013-019>021-103>108-180500-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Northern Cook-Central Cook-Southern Cook-
Northern Will-Southern Will-Eastern Will-
Including the cities of Rockford, Belvidere, Crystal Lake,
Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, Mundelein,
Gurnee, Rochelle, Oregon, Byron, Dixon, DeKalb, Sycamore, Aurora,
Elgin, Naperville, Wheaton, Downers Grove, Lombard, Carol Stream,
Ottawa, Streator, La Salle, Mendota, Marseilles, Oswego, Yorkville,
Plano, Morris, Coal City, Minooka, Evanston, Des Plaines,
Schaumburg, Palatine, Northbrook, Chicago, Cicero, Oak Lawn,
Oak Park, La Grange, Calumet City, Oak Forest, Lemont, Orland Park,
Park Forest, Joliet, Bolingbrook, Plainfield, Mokena, Channahon,
Manhattan, Wilmington, Crete, Peotone, and Beecher
128 PM CDT Thu Jul 16 2026

...AIR QUALITY ALERT IN EFFECT NOW THROUGH FRIDAY NIGHT...

The Illinois Environmental Protection Agency has issued a Red
Forecast Air Pollution Action Day for Friday July 17th for the AirNow
AQI forecast sectors of Rockford and all 6 Chicago area forecast
sectors. This is in addition to downgrade of the ongoing action day
to a Purple Forecast Air Pollution Action Day in effect today.

These Purple and Red Forecast Air Pollution Action Days are declared
due to a forecast of Very Unhealthy-Purple category particulates on
Thursday July 16th and a forecast of Unhealthy-Red category
particulates on Friday July 17th.

Northern IL is on the edge of a thick plume of surface smoke
blanketing the Great Lakes and Northeast U.S. While some models do
suggest minor decreases in smoke/PM2.5 levels are possible today,
they also suggest that the smoke wont significantly decrease until
between mid-morning and mid-afternoon Friday. Forecasts for 24-hour
AQI will remain in poor categories Friday even though condition may
eventually improve. With this in mind, those with air quality
concerns or outdoor plans are encouraged to check current NowCast
readings or sign up for EnviroFlash alerts on AirNow.gov to aid in
both identifying periods of poor AQI and periods of improving AQI.

AQI Category Guidance

Unhealthy - Everyone should reduce prolonged activities or heavy
exertion outdoors. Active children, older adults, and people with
pulmonary or respiratory disease such as asthma should avoid
prolonged activities or heavy exertion outdoors.

Very Unhealthy - Sensitive groups: Avoid all physical activity
outdoors. Reschedule to a time when air quality is better or move
activities indoors. Everyone else: Avoid long or intense activities.
Consider rescheduling or moving activities indoors. Note: If you
don`t have an air conditioner, staying inside with the windows closed
may be dangerous in extremely hot weather. If you are hot, go
someplace with air conditioning or check with your local government
to find out if cooling centers are available in your community.

Hazardous - Everyone: Avoid all physical activity outdoors.
Sensitive groups:
Remain indoors and keep activity levels low. Follow tips for keeping
particle levels low indoors. Note: If you don`t have an air
conditioner, staying inside with the windows closed may be dangerous
in extremely hot weather. If you are hot, go someplace with air
conditioning or check with your local government to find out if
cooling centers are available in your community.

Air quality forecasts, current air quality, and tips on how you can
reduce your emissions can be found at www.airnow.gov

Media Contact... Illinois EPA

$$

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
302 PM CDT Thu Jul 16 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-172015-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
302 PM CDT Thu Jul 16 2026 /402 PM EDT Thu Jul 16 2026/

This Hazardous Weather Outlook is for portions of north central
Illinois...northeast Illinois and northwest Indiana.

.DAY ONE...Tonight.

Weather hazards expected...

  Limited Thunderstorm Risk.
  Limited Excessive Heat Risk.

DISCUSSION...

An isolated thunderstorm is possible prior to sunset this
evening.

Unhealthy air quality due to wildfire smoke is expected through
tonight and may locally reduce visibilities under 1 mile at times,
particularly north and east of I-90.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Friday...
  Limited Thunderstorm Risk.
  Limited Flooding Risk.
  Limited Excessive Heat Risk.
Saturday...
  Limited Thunderstorm Risk...with an associated:
     Level 1 of 5 Severe Thunderstorm Risk.
  Limited Excessive Heat Risk.
Saturday evening through early Sunday morning...
  High Swim Risk at unprotected Lake Michigan beaches.
Monday...
  Limited Thunderstorm Risk.

DISCUSSION...

Scattered showers and thunderstorms are possible Friday
afternoon. There is an additional chance for thunderstorms
Saturday afternoon and evening. Some storms could produce locally
heavy rainfall.

.SPOTTER INFORMATION STATEMENT...

  Spotter activation will not be necessary through tonight.

GENERAL STORM MOTION OF THE DAY:

  Variable at less than 10 mph.

$$

Hazard Report Provided By forecast.weather.gov