Hazard Report Provided By forecast.weather.gov

ILZ005-006-012-013-020-021-103>108-180500-
McHenry-Lake IL-Kane-DuPage-Kendall-Grundy-Northern Cook-
Central Cook-Southern Cook-Northern Will-Southern Will-Eastern Will-
Including the cities of Crystal Lake, Algonquin, McHenry, Woodstock,
Waukegan, Buffalo Grove, Mundelein, Gurnee, Aurora, Elgin,
Naperville, Wheaton, Downers Grove, Lombard, Carol Stream, 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
222 PM CDT Fri Jul 17 2026

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

The Illinois Environmental Protection Agency has determined that the
"Air Pollution Action Day" designation will remain in effect for the
greater Chicago Metropolitan Area through Saturday night July 18th.
Additionally, the ongoing "Purple Forecast Air Pollution Action Day"
designation also remains in effect until midnight tonight.

A Chicago area "Air Pollution Action Day" is declared when weather
conditions are such that widespread ozone and or particulate levels
are expected to be at or above the Unhealthy for Sensitive Groups
(USG) category of the Air Quality Index (AQI) for multiple days.
Ozone is expected to be the primary pollutant of concern although
smoke/PM2.5 may also become a concern later in the work week.

Active children and adults, especially people with pulmonary or
respiratory disease such as asthma, should limit prolonged outdoor
activity.

Area residents are urged to reduce pollution levels. 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
305 PM CDT Fri Jul 17 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-182015-
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-
305 PM CDT Fri Jul 17 2026 /405 PM EDT Fri Jul 17 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 Flooding Risk.

DISCUSSION...

Isolated to scattered thunderstorms are expected through early
this evening. The strongest storms may be capable of gusty winds
up to 50 mph and downpours which may lead to localized flooding.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Saturday...
  Elevated Thunderstorm Risk...with an associated:
     Level 2 of 5 Severe Thunderstorm Risk.
  Limited Excessive Heat Risk.
Saturday Night...
  High Swim Risk at Lake Michigan Beaches.
Monday...
  Elevated Thunderstorm Risk...with an associated:
     Level 2 of 5 Severe Thunderstorm Risk.
Tuesday...
  High Swim Risk at Lake Michigan Beaches.

DISCUSSION...

Additional rounds of thunderstorms are likely Saturday and
Monday, some of which could be strong to severe.

.SPOTTER INFORMATION STATEMENT...

  Spotter activation will not be necessary through tonight.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east at 15 to 20 mph.

$$

Hazard Report Provided By forecast.weather.gov