Boise’s summer weather forecast hotter than usual, but not before another rainy weekend
It’s going to be a long, hot and dry summer, Boise.
That’s nothing new, but in its summer outlook for July through September, the National Weather Service has predicted above-average temperatures and average to below-average rainfall for the Treasure Valley.
How hot will it get? That remains to be seen, but the average temperature will quickly increase in the coming months.
“Above normal could be anything from a degree to 10 degrees; it can be variable,” NWS meteorologist Joel Tannenholz told the Idaho Statesman. “We have no way of forecasting how much above normal.”
The average high in Boise at the beginning of June is 77 degrees and increases to 87 by the end of the month. By the end of July, the average high is 95.
Boise has a 50%-60% chance of above-normal temperatures, according to the NWS. If the above-average weather pattern persists, expect temperatures to be near 100 in late July and early August.
Boise also is leaning toward a summer of below-average rainfall yet is only on the cusp of what’s forecast to be a dry summer for the north and middle parts of the county.
But that forecast shouldn’t cause too much concern, Tannenholz said, because Boise barely sees any rain during the summer regardless.
Since 1940, Boise has averaged only 0.26 inches of precipitation in July, 0.27 inches in August and 0.55 inches in September.
“My understanding is that if we were below normal, it wouldn’t make a whole lot of difference. It’s frankly nothing,” Tannenholz said.
Boise typically doesn’t get a lot of rainfall in the summer, Tannenholz said, because much of the region’s precipitation comes from storms from the Pacific Ocean, and during the summer, the jet stream is too far north to push any storms toward Boise.
He also said the occasional thunderstorm could come into Boise from monsoons to the southwest, but westerly winds often push those storms east of Idaho.
Another rainy weekend for Boise
Following Memorial Day weekend’s downpour that saw Boise pickup over half an inch of rain, this weekend’s forecast paints another wet picture. The NWS is forecasting a 70% chance of rain on Saturday and a 90% chance on Sunday.
If you’re looking to get outside for the weekend, Saturday morning is the time to do it. Tannenholz said the area should expect one-tenth of an inch of rain Saturday morning before up to four-tenths of an inch will fall in the afternoon.
Three-tenths of an inch could fall Sunday morning, Tannenholz said, before light rainfall in the afternoon.
That means Boise could see over three-quarters of an inch of rain from start to finish. The weather will pick up on Monday with a high of 72 degrees and some clouds before a full sun and 76 degrees are forecast for Tuesday.
This story was originally published June 3, 2022 at 12:57 PM.
