Boise, Idaho – Sweltering summer heat will grip much of southwest Idaho through the weekend, with Saturday shaping up as the hottest day of the week. Boise, Nampa, Caldwell and Mountain Home are expected to top out near or above 99 degrees, creating dangerous conditions for anyone spending extended time outdoors.
According to the National Weather Service in Boise, the heat will peak Saturday before monsoonal moisture begins pushing north. That moisture will spark increasing chances for showers and thunderstorms Saturday evening, with activity spreading into the Treasure Valley and central Idaho by Sunday and Monday.
The agency warns that outdoor events, road travel, and backcountry plans could be impacted by rapidly developing storms, especially in higher elevations such as McCall, Stanley and Sun Valley. Lightning, gusty winds and localized downpours are possible.
Residents are urged to limit strenuous activity during peak afternoon hours, drink plenty of water, and check on vulnerable neighbors. Those planning mountain trips should prepare for quick shifts from hot sun to wet storms.
Storm chances are expected to continue into early next week, with scattered showers possible through Wednesday.
Five Day Forecast for Boise, Idaho
- Thursday: High 92°F, dry
- Friday: High 96°F, dry
- Saturday: High 99°F, storm risk late
- Sunday: High 96°F, scattered storms
- Monday: High 94°F, storm chances increase
