A steady warming trend will bring the Treasure Valley from comfortable temperatures in the upper 80s Tuesday to dangerous heat near 100 degrees or above Thursday through Saturday, while widespread wildfire smoke from fires in Washington, Oregon, and Idaho will continue to degrade air quality through the week.
Warming Trend Builds Through the Week
High pressure building over the southwestern United States will drive a steady warming trend across the Treasure Valley through the week. Temperatures will climb from a pleasant 88 degrees Tuesday to 95 degrees Wednesday before the heat intensifies significantly Thursday through Saturday. Lower valley locations will see highs near 101 degrees Thursday, 102 degrees Friday, and 100 degrees Saturday as the upper-level ridge reamplifies over the Great Basin and Four Corners region. Temperatures will run 5 to 10 degrees above normal during this period.
Residents should begin preparing now for the return of dangerous heat. Stay hydrated, limit strenuous outdoor activities during the hottest parts of the afternoon, use air conditioning or visit a cooling center, and check on vulnerable neighbors and family members.
Widespread Smoke and Degraded Air Quality
Wildfire smoke will be a persistent and significant concern through the week. Northwest flow aloft will transport elevated smoke from large fires in Washington and northeast Oregon into the Treasure Valley, combining with smoke from the Tartar fire to create widespread degraded air quality and reduced visibility. Smoke will be most concentrated during the overnight and early morning hours before afternoon mixing provides brief improvements. The smoke may also keep afternoon temperatures a few degrees cooler than forecast during the peak heating days later in the week.
Residents with respiratory conditions, the elderly, children, and others sensitive to smoke should limit outdoor activities, especially during the morning hours, and keep windows and doors closed.
Increased Winds Friday Through the Weekend
Conditions will remain dry and breezy through the weekend. Some weather models are hinting at a possible upper-level trough moving east across the Pacific Northwest on Sunday, which would bring increased wind speeds and enhanced fire weather concerns, though precipitation chances remain near zero.
Central Idaho Mountains
The central Idaho mountains will also experience the warming trend through the week, with temperatures climbing well above normal by Thursday. Widespread smoke impacts will affect the mountains as well, with smoke from multiple large fires in the region creating degraded air quality and reduced visibility. The increased winds Friday through the weekend will create elevated fire weather concerns for the mountains.
Tonight
Widespread smoke, mainly after 9pm. Mostly clear, with a low around 53. Diminishing NW breeze.
Tuesday
Widespread smoke, mainly before noon. Sunny, with a high near 88. Wind W 5-10 mph in the afternoon.
Tuesday Night
Widespread smoke, mainly between 9pm and 10pm. Mostly clear, with a low around 57. Northwest wind 5-10 mph becoming light and variable.
Wednesday
Areas of smoke before 7am. Sunny and hotter, with a high near 95. Light wind.
Wednesday Night
Mostly clear, with a low around 61. Wind becoming calm.
Thursday
Sunny and very hot, with a high near 101.
Thursday Night
Clear, with a low around 65.
Friday
Sunny and very hot, with a high near 102.
Friday Night
Mostly clear, with a low around 64.
Saturday
Sunny and very hot, with a high near 100.
Saturday Night
Mostly clear, with a low around 65.
Sunday
Sunny and not as hot, with a high near 96.
Sunday Night
Mostly clear, with a low around 63.
Monday
Sunny and hot, with a high near 94.
