Extreme Heat Warning

Locations Affected

Saint Louis, MO ∙ Columbia, MO ∙ O'Fallon, MO ∙ Saint Charles, MO ∙ Saint Peters, MO ∙ Florissant, MO ∙ Sauget, IL ∙ Danville, MO ∙ Williamson, IL ∙ Dillard, MO

Full Alert Message

URGENT - WEATHER MESSAGE National Weather Service St Louis MO 206 PM CDT Fri Jul 18 2025 ...EXTREME HEAT WARNING IN EFFECT FROM NOON SATURDAY TO 7 PM CDT WEDNESDAY... * WHAT...Dangerously hot conditions with heat index values up to 110 expected. * WHERE...Portions of southwest Illinois and central, east central, and southeast Missouri. * WHEN...From noon Saturday to 7 PM CDT Wednesday. * 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.

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