228 WWUS73 KLSX 180804 NPWLSX URGENT - WEATHER MESSAGE National Weather Service St Louis MO 304 AM CDT Sat Jul 18 2026 ILZ069-074-079-100>102-MOZ041-047>051-059>065-072>075-084-085-099-182315- /O.CON.KLSX.HT.Y.0004.260718T1700Z-260722T0000Z/ Clinton IL-Washington IL-Randolph IL-Madison IL-Saint Clair IL- Monroe IL-Boone MO-Moniteau MO-Cole MO-Osage MO-Callaway MO- Montgomery MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO- Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO- Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO- Madison MO-Reynolds MO- Including the cities of Union, Fulton, Cahokia, Washington, Saint Louis, Farmington, Chester, Edwardsville, Belleville, Alton, Sullivan, Columbia, Jefferson City, Sparta, and Saint Charles 304 AM CDT Sat Jul 18 2026 ...HEAT ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 7 PM CDT TUESDAY... * WHAT...Heat index values up to 105 expected. * WHERE...Portions of south central and southwest Illinois and central, east central, and southeast Missouri. * WHEN...From noon today to 7 PM CDT Tuesday. * 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. && $$