Extreme Heat Warning

Locations Affected

Saint Louis, MO ∙ Columbia, MO ∙ O'Fallon, MO ∙ Saint Charles, MO ∙ Saint Peters, MO ∙ Florissant, MO ∙ Shiloh, IL ∙ New Memphis, IL ∙ Millersburg, MO ∙ Centreville, IL

Full Alert Message

URGENT - WEATHER MESSAGE National Weather Service St Louis MO 243 PM CDT Mon Aug 10 2026 ...EXTREME HEAT WARNING REMAINS IN EFFECT UNTIL 8 PM CDT WEDNESDAY... * WHAT...Dangerously hot conditions with heat index values up to 110. * WHERE...Portions of south central and southwest Illinois and central and east central Missouri. * WHEN...Until 8 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. People in the Saint Louis Metropolitan Area can get information about cooling centers or energy assistance related to the excessive heat by calling the United Way of Greater Saint Louis at 800-427-4626, or if calling from a land line phone dial 2-1-1. You can also call Cool Down Saint Louis at 314-241-7668.

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