Weather Alerts For Saint Johns, IL

# HEADLINE -------------------- EXTREME HEAT WARNING REMAINS IN EFFECT UNTIL 8 PM CDT /9 PM EDT/ SATURDAY # DETAILS -------------------- WHAT Dangerously hot conditions with heat index values 105 to 110. WHERE All of southern Illinois, southwest Indiana, western Kentucky, and southeast Missouri. WHEN Until 8 PM CDT /9 PM EDT/ Saturday. IMPACTS Heat related illnesses increase significantly during extreme heat and high humidity events. ADDITIONAL DETAILS Overnight low temperatures in the mid 70s will provide little relief from the heat. ISSUED AT Friday, September 4, 2026 at 12:42 AM CDT ISSUED BY National Weather Service Paducah KY HEADER URGENT - WEATHER MESSAGE # 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. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke. Stay cool, stay hydrated, stay informed. # AREAS AFFECTED -------------------- Alexander, Bollinger, Hopkins, Marshall, Scott, Spencer, White, Ballard, Butler, Caldwell, Calloway, Cape Girardeau, Carlisle, Carter, Christian, Crittenden, Daviess, Edwards, Franklin, Fulton, Gallatin, Gibson, Graves, Hamilton, Hardin, Henderson, Hickman, Jackson, Jefferson, Johnson, Livingston, Lyon, Massac, McCracken, McLean, Mississippi, Muhlenberg, New Madrid, Perry IL, Perry MO, Pike, Pope, Posey, Pulaski, Ripley, Saline, Stoddard, Todd, Trigg, Union, Union KY, Vanderburgh, Wabash, Warrick, Wayne IL, Wayne MO, Webster, Williamson Including the cities of Vienna, Murray, Rockport, Shawneetown, Jonesboro, Mount Carmel, Calhoun, Cape Girardeau, Cadiz, Sikeston, Herrin, Perryville, Harrisburg, Morganfield, Henderson, Marion, Golconda, Petersburg, West Frankfort, Doniphan, McLeansboro, Eddyville, Elizabethtown, Cairo, Paducah, Metropolis, Wickliffe, Poplar Bluff, Van Buren, Greenville, Benton, Albion, Princeton, Hickman, Fairfield, Dixon, Mayfield, Piedmont, Evansville, Smithland, Fort Branch, Mount Vernon, Bloomfield, Jackson, New Madrid, Hopkinsville, Bardwell, Owensboro, Carbondale, Murphysboro, Charleston, Mound City, Pinckneyville, Marble Hill, Boonville, Elkton, Clinton, Madisonville, Carmi, and Poseyville

Pollen Index: 11.2 Pollen Level: high Predominant Pollen: Ragweed, Chenopods and Nettle. Pollen concentrations for Saturday will be at about the same level in the extremely high range. If you do suffer from allergies, tomorrow should be about as difficult outdoors as it was today.