Boise, Idaho – A stretch of scorching heat builds across southwest Idaho as temperatures climb into the 90s starting Tuesday, with little overnight relief. Tuesday will hit a high of 87°F under sunny skies, but the real heat arrives by Juneteenth, when Boise could see 94°F — the hottest day of the year so far.
According to the National Weather Service in Boise, Tuesday begins calm, but west-northwest winds could pick up to 8 mph by late morning. Wednesday and Thursday will intensify the heat, with highs reaching 93°F and 94°F, respectively. Overnight lows will offer only mild cooling, staying near 57–59°F. Hydration and limiting outdoor activity during peak hours are strongly advised.
Urban areas like Boise, Meridian, and Nampa will experience higher heat retention, especially near paved surfaces like I-84. Rural fire risk may increase with dry winds Wednesday afternoon. Cooling shelters may open if extreme heat persists. Local officials urge residents to check on vulnerable neighbors and avoid strenuous activities after 11 a.m.
Looking ahead, the weekend brings mild relief. Friday tops out near 85°F with cooler lows, dipping into the upper 40s by Saturday night. Sunday highs will fall to the upper 70s, offering a break before heat rebuilds early next week.
⚠️ Stay weather-aware: more heat alerts are possible later this week.
🌤️ Five-Day Forecast for Boise, ID (June 17–21)
- Tuesday: Sunny, high 87°F, low 57°F
- Wednesday (Juneteenth): Sunny, high 93°F, low 59°F
- Thursday: Sunny, high 94°F, low 57°F
- Friday: Mostly sunny, high 85°F, low 50°F
- Saturday: Mostly sunny, high 77°F, low 45°F
