Boise, Idaho – Much of southern Idaho is set to bake under a dome of high pressure this week, with temperatures rising into the 90s and little relief in sight by the weekend.
According to the National Weather Service in Boise, a weak high-pressure system early in the week will give way to stronger ridging, pushing highs into the low- to mid-90s by Sunday, June 29. The warming trend begins Monday and accelerates by midweek, with cities like Boise, Caldwell, and Twin Falls expected to reach 94–95°F on Sunday.
Caldwell and Mountain Home will see daily highs near or above 90°F starting Wednesday. McCall remains cooler, but even this higher-elevation area will climb into the mid-80s by Friday. Overnight lows throughout the week will range from the 40s in McCall and Baker City to the upper 50s in lower valleys like Nampa and Ontario…