Extreme Heat Warning

Locations Affected

Saint Louis, MO ∙ O'Fallon, MO ∙ Saint Charles, MO ∙ Saint Peters, MO ∙ Florissant, MO ∙ Affton, MO ∙ Beverly Hills, MO ∙ Ozora, MO ∙ Shiloh, IL ∙ New Memphis, IL

Full Alert Message

URGENT - WEATHER MESSAGE National Weather Service St Louis MO 123 AM CDT Mon Jun 29 2026 ...EXTREME HEAT WARNING NOW IN EFFECT UNTIL 10 PM CDT FRIDAY... * WHAT...Dangerously hot conditions with heat index values up to 112. * WHERE...Portions of south central and southwest Illinois and east central and southeast Missouri. * WHEN...Until 10 PM CDT Friday. * 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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