The National Weather Service in Boise issued a Heat Advisory for portions of south central and southwest Idaho and southeast Oregon on August 19, affecting residents across Ada County and the broader Treasure Valley region. The advisory remains in effect through Friday, August 21 at 9:00 PM MDT, with dangerously high temperatures expected to peak between 98 and 104 degrees.
What to Expect During the Heat Advisory
The advisory began at noon MDT Thursday and will continue through Friday evening, creating a roughly 45-hour window of elevated heat risk for the region. Residents and workers throughout Boise, Meridian, Eagle, Kuna, and surrounding Ada County communities should take precautions to avoid heat-related illness during this period.
High temperatures in this range can pose serious health risks, particularly for outdoor workers, children, elderly residents, and those with underlying health conditions. The National Weather Service emphasized that heat illnesses are possible during such conditions, and heat stroke represents a medical emergency requiring an immediate 911 call.
Safety Recommendations for Outdoor Work
The Occupational Safety and Health Administration recommends that workers exposed to heat take frequent rest breaks in shaded or air-conditioned environments. Those working outdoors should schedule strenuous tasks for early morning or evening hours when temperatures are cooler, stay hydrated with water rather than caffeine or alcohol, and monitor themselves and coworkers for signs of heat exhaustion or heat stroke, including dizziness, nausea, rapid heartbeat, and confusion.
Construction workers, agricultural workers, landscapers, and others whose jobs require prolonged outdoor exposure should prioritize these precautions during the advisory period. Employers should ensure adequate shade, water, and rest time for their crews to prevent workplace heat injuries.
Staying Safe at Home and in the Community
Residents should limit outdoor activities during the hottest parts of the day, typically between 11 AM and 5 PM. If air conditioning is not available at home, public facilities such as libraries, community centers, and shopping malls throughout Ada County offer air-conditioned refuge. The Boise Parks and Recreation Department also maintains public cooling centers during extreme heat events.
Keep pets indoors or in shaded areas with plenty of water, and never leave children or animals unattended in vehicles, where temperatures can reach dangerous levels within minutes. Wear light-colored, lightweight, and loose-fitting clothing to help your body regulate temperature.
Those planning outdoor recreation—such as floating the Boise River or attending community events like the Korean Culture Festival—should apply sunscreen, wear hats, drink water frequently, and take breaks in shaded areas or air-conditioned spaces.
What Comes Next
The Heat Advisory is scheduled to expire at 9:00 PM MDT on Friday, August 21. Residents should monitor updates from the National Weather Service Boise office for any extensions or changes to the advisory. Check local news and weather forecasts regularly for the latest conditions and safety guidance as temperatures peak over the next two days.