Extreme Heat Warning

Locations Affected

Tucson, AZ ∙ Nogales Intl Airport, AZ ∙ Calva, AZ ∙ Santa Rosa Valley, AZ ∙ Valencia West, AZ ∙ Ajo, AZ ∙ San Miguel, AZ ∙ Casas Adobes, AZ ∙ Campo Bonito, AZ ∙ Fort Thomas, AZ

Full Alert Message

URGENT - WEATHER MESSAGE National Weather Service Tucson AZ 103 PM MST Mon Aug 18 2025 ...EXTREME HEAT WARNING IN EFFECT FROM 10 AM WEDNESDAY TO 8 PM MST FRIDAY... * WHAT...Dangerously hot conditions with temperatures ranging from 105 to 110 across much of Pima and southeastern Pinal counties leading to widespread Major Heat Risk. In other areas of southeastern Arizona, high temperatures will range from 100 to 105 degrees. * WHERE...South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, and Western Pima County. * WHEN...From 10 AM Wednesday to 8 PM MST Friday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. * ADDITIONAL DETAILS...Major Heat Risk is when heat will affect anyone without cooling or hydration as well as health systems and industries. PRECAUTIONARY/PREPAREDNESS ACTIONS... 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. 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 and drink plenty of water.

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