Goodbye, sun. Hello, rain, cold ... and snow? Changes are coming to Boise this weekend
It looks like this weekend will finally mark the end of summer-like weather in Boise.
After an unusually warm start to October — Boise’s high temperature has not dipped below 72 — a cold front from the Bering Sea and the Gulf of Alaska is preparing to sweep over the Gem State this weekend.
High temperatures in Boise will plummet from 75 degrees on Thursday to 52 on Saturday. Low temperatures overnight on Saturday and Sunday will hover near freezing throughout the Treasure Valley.
Along with the cold front, widespread precipitation will envelop Idaho, providing up to two-thirds of an inch in Boise and several inches of snow in elevations above 5,000 feet.
“We had this big dome of high pressure, warm temperatures over us. Usually, when we get high pressure, it’s usually warmer air,” Chuck Redman, a meteorologist with the National Weather Service in Boise, told the Idaho Statesman on Thursday. “That is being pushed out of the way as we get a significant cold front coming through the Bering.”
The dome of high-pressure Redman referenced was a Rex block, which kept cold air and moisture from penetrating the Northwest, instead pushing it into Canada.
Falling temperatures should alert residents with vegetation in their gardens; temperatures in the 29-32 range will kill tender plants such as cucumbers, pumpkins and tomatoes.
The Weather Service gave Boise just a 3% chance of dropping below 32 degrees, but other locations around the Treasure Valley, such as Nampa and Caldwell, have a 61% chance of dropping below freezing.
The rain expected to hit Boise will be the first precipitation the city has seen in October and the heaviest to fall since 0.79 inches of rain dropped on the city on June 12.
The Weather Service also said Idaho should see its first real snowfall of the season at elevations above 5,000 feet, which would include Bogus Basin. Elevations above 7,000 feet could see locally heavier snow, Redman said.
“Down at the McCall level, it’ll be just under an inch,” he said. “But way up in the higher elevations, we could see several inches of snow.”
McCall sits just above 5,000 feet.
The end of warmer weather
Despite the difficulties of forecasting too far into the future, Redman said he feels confident that Boise is finally about to turn its back on warmer temperatures for good.
Boise’s seven-day forecast shows an active pattern of rainfall and high temps that aren’t warmer than the mid-50s.
Redman said that pattern should continue at least into November. By that point, a day above 70 degrees would be abnormal — the average temperature in Boise at the start of November is around the 50-degree mark and drops to around 40 degrees by the end of the month.
This story was originally published October 20, 2022 at 12:48 PM.
