Boise, Idaho

weather for boise.

Basin, Semi-Arid, Continental43.6150° N · 116.2023° W

Boise sits at the eastern edge of the Snake River Plain — a semi-arid sagebrush basin that the Boise Front rises out of immediately northeast, and the geometry produces a continental climate with four hard seasons. Pacific moisture mostly wrings out over the Cascades and Blue Mountains before it reaches Boise; what gets through arrives modified, drier, and quieter than the rain on the western side of the state. Summer is hot and dry, winter is cold and inverted, and the spring and fall are short and beautiful.

Live conditionsBoise, Idaho
Updated just now
71°FClear skyFeels like 69°
Humidity
31%
Wind
7mph
UV Index
4
Visibility
6.2mi
Sunrise7:11 AM
Sunset8:20 PM
8-day forecast
  1. Today71°40°
  2. Fri71°46°39%
  3. Sat63°50°100%
  4. Sun63°45°100%
  5. Mon53°44°100%
  6. Tue57°38°
  7. Wed58°49°100%
  8. Thu54°36°64%

Today’s brief

what vesper sounds like in boise.

Smoke is layering in from the Salmon-Challis fires — visibility down to four miles by ten o’clock and the AQI is climbing through the orange band. The forecast high is ninety-six but the air is going to feel heavier than the temperature suggests. Stay inside if you can.

— Vesper, Boise · Friday

Local weather

what makes boise weather unique.

Snake River Plain semi-arid regime (~12 in annual rainfall)
Cascade and Blue Mountain rain shadow effect
Winter cold-air pool basin inversion
Summer wildfire smoke transport
Strong diurnal temperature range
Sunset VerifyTonight · 8:20 PM
34/ 100
FAIRFair — unremarkable

Approximation from atmospheric data. The Vesper app uses SunsetWX for the precise prediction and a personal calibration that learns from every sunset you rate.

Editorial note

sunsets in boise.

Boise sunsets are best from the Boise Foothills trail system above the city, where the unobstructed western horizon over the Snake River Plain stretches a hundred miles toward Oregon. Post-cold-front evenings produce the cleanest light, when continental air has flushed the basin of summer smoke and dust. Camel’s Back Park and the Table Rock summit are the iconic urban viewpoints.

Unlike Apple Weather, Vesper writes the Boise sky as the embodied experience it actually is, not a temperature number with a generic icon.

What is the best weather app for Boise?

Vesper is the best weather app for Boise because it reads the Snake River Plain as a semi-arid basin with continental seasons rather than a generic Pacific Northwest forecast. The brief tracks the Cascade and Blue Mountain rain shadow that wrings most Pacific moisture out before it reaches the basin, the winter cold-air pool inversions that trap haze in the valley, and the summer wildfire smoke that arrives from Idaho and Pacific Northwest fires — because Boise’s continental atmosphere is its own climate, distinct from the wet side of Idaho.

Frequently Asked Questions

Why is Boise so much drier than the rest of Idaho?

Boise sits in the rain shadow of multiple mountain ranges. Pacific storms encounter the Cascades, Coast Range, and Blue Mountains before reaching the Snake River Plain, and most of the moisture precipitates out on the windward sides of those ranges. By the time the air descends into the Boise basin, it has lost the bulk of its water content. Boise averages only 12 inches of precipitation annually — drier than most of the West Coast and dramatically drier than the Idaho Panhandle.

What causes Boise’s winter cold-air pool inversions?

The Boise Front and surrounding terrain create a partially enclosed basin. In winter, dense cold air settles into the bottom of the basin and warm air aloft caps it — producing a persistent temperature inversion where the valley floor sits in cold haze while the surrounding hills remain in clear sky. Inversions can persist for days at a time and produce the city’s worst air quality of the year, until a strong storm system or warm front breaks the pattern.

How does wildfire smoke affect summer weather in Boise?

The Salmon-Challis National Forest, the Frank Church-River of No Return Wilderness, and the Pacific Northwest fire complexes all sit upwind of Boise during summer. Smoke from active fires can transport hundreds of miles on prevailing westerlies and settle into the Boise basin, producing AQI readings in the unhealthy range for days or weeks at a time during peak fire season (July through September). The smoke typically clears with the first significant cold front of fall.

Get Vesper

your first boise brief, on us.