Extreme Heat Watch

Locations Affected

Saint Louis, MO ∙ O'Fallon, MO ∙ Saint Charles, MO ∙ Florissant, MO ∙ Saint Peters, MO ∙ Roxana, IL ∙ Cedar Hill, MO ∙ Country Life Acres, MO ∙ Olivette, MO ∙ Maplewood, MO

Full Alert Message

URGENT - WEATHER MESSAGE National Weather Service St Louis MO 203 AM CDT Fri Jun 20 2025 ...EXTREME HEAT WATCH REMAINS IN EFFECT FROM SATURDAY AFTERNOON THROUGH TUESDAY EVENING... * WHAT...Dangerously hot conditions with heat index values up to 109 possible. * WHERE...In Illinois, Jersey IL, 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 Saturday afternoon through Tuesday evening. * 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. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes. Monitor the latest forecasts and warnings for updates. If you do not have air conditioning in your home or lack shelter, you can call 211 for assistance locating appropriate shelter from the heat.

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