Unseasonably warm high pressure remains firmly locked over the Treasure Valley, keeping afternoon temperatures 10 to 20 degrees above normal through the end of the workweek. Daily highs in Boise will hover near mid-80s through Friday—coming exceptionally close to matching or breaking long-standing daily high temperature records.
Sizzling temps continue until the weekend in Scott Dorval's video forecast
Expect mostly clear skies, light winds, and crisp, cool nights with large diurnal swings, bringing evening lows back down into the 50s.
While most of the region stays completely dry through Friday, a weak upper-level system moving east across Nevada could spark isolated thunderstorms along the Idaho/Nevada border late Monday afternoon and evening. These high-based storms may generate sudden, gusty outflow winds reaching up to 40 mph.
Major Weekend Pattern Change Brings Breezy Conditions and Drops Temperatures
Enjoy the unseasonal warmth while it lasts. A strong upper-level trough pushing through the Pacific Northwest will force a sharp cold front across the region on Saturday, signaling a dramatic shift to true autumn weather.
Winds will pick up across mountain terrain on Friday (gusts 20–30 mph) before breezy conditions spill into lower valleys over the weekend. Temperatures will drop 10 to 15 degrees on Saturday, with additional cooling expected Sunday and Monday as an upper-level closed low deepens overhead.
Along with the temperature plunge, shower chances return to the forecast late Saturday night through Columbus Day. Central and South-Central Idaho hold the highest likelihood for precipitation (20–40% chance of rain and high-mountain snow), while western valleys see a 10–20% chance of rain showers accompanied by patchy morning fog.
Boise Temperature Forecast vs. Daily Records (Today – Friday)
| Day | Forecast High (°F) | Historical Record High (°F) | Year Record Set |
| Monday (Oct 5) | 86° | 86° | 1904 / 1920 |
| Tuesday (Oct 6) | 86° | 87° | 1988 |
| Wednesday (Oct 7) | 86° | 86° | 1980 |
| Thursday (Oct 8) | 86° | 88° | 1910 |
| Friday (Oct 9) | 86° | 90° | 2015 |
Tonight
Mostly clear, with a low around 54. West northwest wind around 6 mph becoming calm in the evening.
Tuesday
Sunny, with a high near 86. Calm wind becoming west around 6 mph in the afternoon.
Tuesday Night
Clear, with a low around 52. Light wind.
Wednesday
Sunny, with a high near 86. Light wind.
Wednesday Night
Clear, with a low around 52. Light wind.
Thursday
Sunny, with a high near 86.
Thursday Night
Clear, with a low around 54.
Friday
Sunny, with a high near 86.
Friday Night
Partly cloudy, with a low around 53.
Saturday
Mostly sunny & much cooler, with a high near 72.
Saturday Night
A 20 percent chance of showers. Partly cloudy, with a low around 44.
Sunday
Mostly sunny and cooler than normal, with a high near 63.
Sunday Night
A 20 percent chance of showers. Partly cloudy, with a low around 40.
Columbus Day
A 20 percent chance of showers. Patchy fog. Otherwise, mostly sunny, with a high near 61.
