719 WWUS73 KLOT 300651 NPWLOT URGENT - WEATHER MESSAGE National Weather Service Chicago IL 151 AM CDT Tue Jun 30 2026 ILZ003>006-008-010>013-019>021-023-032-033-039-106>108-INZ001-002-010-011-019-301700- /O.UPG.KLOT.HT.Y.0001.000000T0000Z-260702T0300Z/ /O.EXB.KLOT.XH.W.0001.000000T0000Z-260703T0500Z/ Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-Northern Will-Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper- Benton- Including the cities of Rockford, Streator, Mendota, Yorkville, Channahon, Wheaton, Portage, Algonquin, Minooka, Bourbonnais, DeKalb, Dixon, Oregon, Mundelein, Chesterton, Crystal Lake, Sycamore, Belvidere, Ottawa, Marseilles, Wilmington, Morocco, Fairbury, Rensselaer, Naperville, DeMotte, Crete, Roselawn, Gibson City, Woodstock, Dwight, Lombard, Hammond, La Salle, Pontiac, Plano, Fowler, Waukegan, Elgin, Bolingbrook, Byron, Plainfield, Gary, Kentland, Mokena, Kankakee, Coal City, Gilman, Paxton, Beecher, Rochelle, Bradley, Joliet, Peotone, McHenry, Oswego, Morris, Valparaiso, Watseka, Oxford, Manhattan, Merrillville, Downers Grove, Carol Stream, Buffalo Grove, Gurnee, and Aurora 151 AM CDT Tue Jun 30 2026 /251 AM EDT Tue Jun 30 2026/ ...EXTREME HEAT WARNING IN EFFECT UNTIL MIDNIGHT CDT /1 AM EDT/ THURSDAY NIGHT... * WHAT...Dangerously hot conditions with heat index values around 105 expected each afternoon. * WHERE...Portions of central, east central, north central, and northeast Illinois and northwest Indiana. * WHEN...Until midnight CDT /1 AM EDT/ Thursday Night. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS...Dangerous heat is now expected to persist through Thursday. Thunderstorms may begin to bring some relief from the heat for portions of northern Illinois by Thursday afternoon or evening. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes. && $$ ILZ103>105-301700- /O.EXT.KLOT.XH.W.0001.000000T0000Z-260703T0500Z/ Northern Cook-Central Cook-Southern Cook- Including the cities of Evanston, Park Forest, Oak Park, Schaumburg, Chicago, La Grange, Oak Forest, Cicero, Oak Lawn, Lemont, Calumet City, Northbrook, Des Plaines, Palatine, and Orland Park 151 AM CDT Tue Jun 30 2026 ...EXTREME HEAT WARNING NOW IN EFFECT UNTIL MIDNIGHT CDT THURSDAY NIGHT... * WHAT...Dangerously hot conditions with heat index values around 105 expected each afternoon. * WHERE...Central Cook, Northern Cook, and Southern Cook Counties. * WHEN...Until midnight CDT Thursday Night. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS...Dangerous heat is now expected to persist through Thursday. Thunderstorms may begin to bring some relief from the heat by Thursday afternoon or evening. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. The magnitude of anticipated heat, combined with oppressive warmth at night will lead to hazardous conditions, particularly for the elderly and those with pre-existing health conditions. Residents of the city of Chicago can call 3 1 1 to request well being checks for elderly friends or family members, or for information on finding the nearest cooling center. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes. && $$