Idaho’s Treasure Valley warmed quickly through the late morning as bright sunshine spread across Boise and dry air settled over southwestern Idaho. Sidewalks already felt warm before noon, and temperatures are on track to surge toward early-summer levels through Memorial Day.
According to the National Weather Service, Boise could hit 92 degrees Monday afternoon under mostly sunny skies with gusty winds developing later in the day. A weak disturbance may trigger isolated afternoon thunderstorms near the foothills and higher terrain, though widespread severe weather is not expected.
The heat marks one of the warmest stretches so far this season across the western United States. Dry conditions continue today with highs near 87 degrees and calm morning winds turning northwest during the afternoon. Travelers along I-84 from Nampa through Boise and Mountain Home should see excellent driving conditions through Monday evening.
The weather pattern changes sharply by Tuesday. Cooler Pacific air pushes inland, knocking highs down into the mid-60s with stronger northwest winds gusting near 25 mph. Clouds increase Tuesday night as scattered showers develop across southern Idaho.
By Wednesday and Thursday, Boise enters a more unsettled spring pattern. Showers and isolated thunderstorms become more common during the afternoon and evening hours. Temperatures cool nearly 20 degrees compared to Monday’s peak heat.
Higher elevations across central Idaho could also see periods of gusty mountain showers later this week as broader Pacific energy spreads inland across the Northwest. While snow levels remain high, cooler air will end the recent stretch of unseasonably warm weather across much of the region.
Long-range outlooks still suggest another warming trend may develop heading into early June.
Five Day Forecast for Boise, Idaho:
- Monday: Mostly sunny and hot, high near 92°F
- Tuesday: Partly sunny, cooler, high near 66°F
- Wednesday: Chance of showers and thunderstorms, high near 72°F
- Thursday: Chance of showers and thunderstorms, high near 79°F
- Friday: Chance of showers and thunderstorms, high near 75°F
