Boise, Idaho – Afternoon temperatures could climb into the low to mid-80s by Thursday in Boise, marking a sharp warmup as a powerful ridge of high pressure builds across the western United States during the first full days of spring.
According to the National Weather Service Climate Prediction Center, the pattern developing Wednesday through Sunday, March 18–22, strongly favors above-normal temperatures across the Intermountain West, including much of Idaho. Highs across the Treasure Valley may run 15 to 20 degrees above typical mid-March levels, with Boise reaching the low to mid-80s during the warmest part of the week.
Communities across southern Idaho including Twin Falls, Nampa and Caldwell could also experience highs pushing into the upper 70s and lower 80s under mostly clear skies.
The warming trend will arrive with limited precipitation chances across much of the region, allowing dry air to dominate valleys and high desert terrain. Climate outlooks show below-normal precipitation probabilities across large portions of the interior West, a setup that allows daytime heating to intensify quickly.
Wind could also become a factor across open terrain and along major travel corridors. Afternoon gusts between 25 and 35 mph may develop across parts of southern Idaho and along Interstate 84, especially during the peak heating hours of the afternoon.
While Idaho warms significantly, other parts of the country remain closer to seasonal norms. New England states, Michigan and Florida are expected to stay near average for mid-March, while northern New England and the Pacific Northwest show stronger chances for above-normal rainfall during the same period.
Forecasters say the western heat surge may peak late in the week before larger atmospheric shifts begin changing conditions across the region early the following week.
