Boise, Idaho – Drivers and residents across southwest Idaho should prepare for intense heat and possible evening thunderstorms Tuesday as a summer weather alert takes effect. High temperatures in Boise are expected to surge to 98°F by Tuesday afternoon, with isolated storms developing after 9 p.m. along the I-84 corridor and surrounding areas.
According to the National Weather Service, a weak frontal boundary will trigger a 20% chance of thunderstorms Tuesday night, particularly in Ada and Canyon counties. Winds will shift northwest at 7 mph in the afternoon before calming after dark. The NWS notes that Wednesday brings a higher chance of showers and thunderstorms after 9 a.m., with a 40% chance of rain expected.
In the heat of the day, pavement and sidewalk temperatures will easily exceed 120°F. Limit outdoor activity, hydrate frequently, and avoid leaving pets or children in vehicles — even for a minute. If lightning occurs, seek shelter indoors immediately and avoid travel on exposed roads such as State Highway 55 or U.S. Route 20.
Though some cloud cover may break the heat Wednesday, temperatures will remain near 90°F until at least Saturday. No significant cooling trend is expected before the weekend.
More storms are possible Wednesday and again late Friday, though most days will stay dry and hot. Updates will be issued if storm chances increase or advisories are posted.
🌤 Boise Five-Day Forecast (June 9–14)
- Monday (June 9): Sunny, high near 97°F
- Tuesday: Sunny, hot, high 98°F; 20% chance of evening T-storms
- Wednesday: 40% chance of showers/T-storms after 9 a.m., high near 90°F
- Thursday: Sunny and hot, high near 90°F
- Friday: Sunny, high near 88°F; more clouds and possible showers Friday night
