# HEADLINE
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EXTREME HEAT WARNING REMAINS IN EFFECT UNTIL 10 PM CDT FRIDAY
# DETAILS
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WHAT
Dangerously hot conditions with heat index values up to 111.
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.
ISSUED AT
Tuesday, June 30, 2026 at 1:20 AM CDT
ISSUED BY
National Weather Service St Louis MO
HEADER
URGENT - WEATHER MESSAGE
# PRECAUTIONARY/PREPAREDNESS ACTIONS
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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.
# AREAS AFFECTED
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Monroe IL, Saint Louis City MO, Clinton IL, Franklin MO, Jefferson MO, Madison IL, Randolph IL, Saint Charles MO, Saint Clair IL, Saint Louis MO, Sainte Genevieve MO, Warren MO, Washington IL
Including the cities of Sparta, Cahokia, Union, Belleville, Sullivan, Edwardsville, Chester, Saint Charles, Washington, Saint Louis, and Alton
