Boise, Idaho – Triple-digit heat will grip the Treasure Valley by Wednesday as temperatures in Boise climb to 100°F under mostly sunny skies. With dry conditions and lingering smoke, residents are urged to limit strenuous outdoor activity between 1 and 6 p.m., especially near heat-reflective surfaces along I-84 and I-184.
According to the National Weather Service in Boise, northwest winds will increase Wednesday afternoon to around 6 mph, offering little relief from the intense sun. Thursday and Friday will bring more of the same, with clear skies and highs holding steady near 100°F. Overnight lows will hover in the mid-60s, offering only minimal cooling.
The heat builds after a brief break earlier this week, and it comes with wildfire smoke concerns. Patchy smoke lingers Tuesday night into early Wednesday, but conditions should improve by midweek. Residents with respiratory issues should monitor air quality updates closely.
Looking ahead, the weekend remains sunny and hot, though Saturday will be slightly cooler with a high near 97°F. Sunday marks the start of a subtle cooldown, with highs dipping to the low 90s and Monday continuing that trend at 92°F. While no storms are in sight, prolonged exposure to extreme heat can stress both infrastructure and individuals.
☀️ Five-Day Boise Weather Outlook (Wed, July 16 – Mon, July 21):
- Wednesday: Sunny, 100°F / 63°F — Breezy afternoon, smoky early.
- Thursday: Sunny, 100°F / 67°F — Hot, dry air continues.
- Friday: Sunny, 100°F / 66°F — No relief from heat.
- Saturday: Sunny, 97°F / 63°F — Slightly cooler, still intense sun.
- Sunday: Sunny, 94°F / 62°F — Cooling trend begins.
- Monday: Sunny, 92°F / 62°F — Comfortable start to the week.
