Idaho could see hottest days of 2026. How long will heat wave last?
A West Coast heat wave is pushing into Idaho, bringing unseasonably warm weather.
A strong high-pressure system “building inland will result in record-high temperatures” starting Tuesday, March 17, the National Weather Service said in its most recent Idaho state forecast discussion.
Wednesday, March 18, through Friday, March 20, could be among the warmest days ever recorded so early in the year,” the weather service said.
Here’s what to know about the forecast for the week ahead:
How hot will it get in Idaho?
The heat wave is expected to last for most of the week before temperatures cool off on Sunday, according to the weather service.
According to the National Weather Service, six Idaho cities are expected to set new maximum temperature records this week, including Boise.
Baker City, Burns, Jerome, McCall and Ontario could also see record-breaking heat.
Warm weather is hitting during a crucial time for the Gem State’s snowpack.
“The warm weather will accelerate snowmelt at mid-to-high elevations and lead to increased flows in small streams and creeks in central and eastern Idaho,” the weather service said.
However, Idaho is not at risk to severe flooding, forecasters said.
When will Bogus Basin close for ski season?
Bogus Basin will close for the winter ski season on Sunday, March 22, weeks earlier than usual, the Idaho Statesman previously reported.
“Operations could extend if conditions allow,” the ski resort said in a Friday, March 13, news release.
What’s in the forecast for Boise?
According to the National Weather Service’s most recent seven-day forecast for Boise, the City of Trees will see hot, sunny weather for most of the week.
On Tuesday, Boise was expected to have a high temperature about 72 degrees and an overnight low temperature of 47 degrees.
Wednesday, Thursday and Friday will be the hottest days of the week, with high temperatures hovering in the low 80s.
Overnight lows will range between the high 40s and the low 50s on these days, the weather service said.
Only partial relief is expected on Saturday as the high makes a 10-degree drop to 72. The overnight low will be 41.
The next cooling trend will arrive on Sunday, as the high drops another 10 degrees to 62.
Sunday will have an overnight low of 41 degrees.
What are flood risks in Idaho?
Predictions for melting mountain snow coincide with Idaho Flood Awareness Week, which started March 15 and runs through Sunday, March 22.
“As spring snowmelt and seasonal rain increase the risk of flooding, the Idaho Office of Emergency Management is raising awareness about the potential dangers flooding poses,” the state office said on its website.
Emergency management will host an educational webinar on Wednesday afternoon, March 19 at 1 p.m.
“This webinar provided insights on how to prepare for, respond to, and mitigate the impacts of spring flooding in Idaho,” the Idaho Office of Emergency Management said.
In addition, the National Weather Service offices across Idaho will share information on flood preparedness daily on social media.
The National Weather Service shared tips to “prepare for flooding before it happens” in a X post on Monday, March 16.
They include:
- Find out if you’re in a flood plain.
- Determine which roads are likely to flood.
- Identify the fastest way to higher ground.
This story was originally published March 17, 2026 at 1:29 PM.
