Hottest ever August in Boise? ‘Looks like a sure thing to me,’ says NWS meteorologist

Boise’s weather this weekend is going to feel frigid.

Well, perhaps not frigid, but for a summer that’s seen Boise record the most 100 degrees days in a year — a stat that’s been tracked since 1875 — it’s going to feel quite cool. For the first time since Aug. 6, Boise’s high temperature will fail to eclipse the 90-degree mark this weekend.

The National Weather Service in Boise is forecasting a high of 88 degrees on Saturday — which is right on average for this time of the year — and a high of 83 on Sunday. Temperatures will dip as low as 55 degrees on Saturday night.

The last time Boise had a high temperature as low as 83 was on July 4 (82 degrees), and the previous time temps were as low as 55 was on June 25 (51 degrees).

The cooler weather results from a weather system passing through Idaho from the Gulf of Alaska, Weather Service meteorologist Joel Tannenholz told the Idaho Statesman on Friday.

“It will be coming in Saturday night; the cold front ahead of it is going to be passing through the area tomorrow during the day,” Tannenholz said. “And it’s really dry; there’s a lot of very dry air coming in behind the cold front.”

Hottest August on record

But don’t whip out your pumpkin spice lattes and wool hats just yet. As quickly as temperatures cool in the Treasure Valley, they’ll be shooting right back up midway through next week.

A warm high-pressure ridge will build over the Pacific Northwest in the aftermath of the colder system, Tannenholz said, bringing clear skies and hotter temperatures.

The Weather Service forecasts a high of 101 degrees on Wednesday and 100 on Thursday. If both predictions are correct, it’ll extend Boise’s record of 100-degree-plus days in a single year from 22 to 24. The previous record was 20 days in 2003.

The continued above-average temperatures through the remainder of the month will also solidify this August as the hottest-ever August on record in Boise, according to Tannenholz.

The current forecasted average temperature for August — considering both high and low temperatures — is 81.7 degrees, Tannenholz said. The current record, which has been tracked since 1877, is 78.7 degrees in 2001.

“It’s not going to be official until the first of September when they have all the data together,” Tannenholz said. “But it looks like a sure thing to me.”