411 WWUS73 KLSX 271815 NPWLSX URGENT - WEATHER MESSAGE National Weather Service St Louis MO 115 PM CDT Sat Jun 27 2026 ILZ100>102-MOZ061-063>065-280915- /O.UPG.KLSX.XH.A.0001.260628T1700Z-260703T0500Z/ /O.NEW.KLSX.XH.W.0001.260628T1700Z-260703T0500Z/ Madison IL-Saint Clair IL-Monroe IL-Saint Charles MO-Saint Louis MO-Saint Louis City MO-Jefferson MO- Including the cities of Alton, Edwardsville, Belleville, Saint Louis, Saint Charles, and Cahokia 115 PM CDT Sat Jun 27 2026 ...EXTREME HEAT WARNING IN EFFECT FROM NOON SUNDAY TO MIDNIGHT CDT THURSDAY NIGHT... * WHAT...Dangerously hot conditions with heat index values up to around 110 expected. * WHERE...In Illinois, Madison IL, Monroe IL, and Saint Clair IL Counties. In Missouri, Jefferson MO, Saint Charles MO, Saint Louis City MO, and Saint Louis MO Counties. * WHEN...From noon Sunday to midnight CDT Thursday Night. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. 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. Young children and pets should never be left unattended in vehicles under any circumstances. Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1. && $$ ILZ058>060-064-065-069-070-074-079-095>099-MOZ018-019-026-027-034>036-041-042-047>052-059-060-062-072>075-084-085-099-280915- /O.CON.KLSX.HT.Y.0002.260628T1700Z-260703T0500Z/ Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL- Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL- Calhoun IL-Jersey IL-Knox MO-Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-Lincoln MO-Gasconade MO-Warren MO- Franklin MO-Crawford MO-Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-Madison MO-Reynolds MO- Including the cities of Farmington, Vandalia, Salem, Mexico, Hannibal, Quincy, Washington, Mount Sterling, Sullivan, Litchfield, Centralia, Sparta, Chester, Pittsfield, Columbia, Bowling Green, Jefferson City, Fulton, and Union 115 PM CDT Sat Jun 27 2026 ...HEAT ADVISORY REMAINS IN EFFECT FROM NOON SUNDAY TO MIDNIGHT CDT THURSDAY NIGHT... * WHAT...Heat index values up to around 105 expected. * WHERE...Portions of south central, southwest, and west central Illinois and central, east central, northeast, and southeast Missouri. * WHEN...From noon Sunday to midnight CDT Thursday Night. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. 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. Young children and pets should never be left unattended in vehicles under any circumstances. Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1. && $$ Elmore