Will Boise weather break another record? Here’s how hot it could get and when
After logging its wettest April on record, the Boise area kicked off the month of May with a heat wave.
Now the weather’s about to get even hotter.
Boise could soon see its first 90-degree day of the year, according to David Groenert, a meteorologist at the Boise office of the National Weather Service.
“The last couple weeks have been dry here,” Groenert told the Idaho Statesman via phone. “Certainly we’ve warmed up. Our temperatures have been above normal.”
Here’s how hot it could get:
Will Boise break heat records?
The Boise area could see high temperatures above 90 degrees on Mother’s Day, Sunday, May 10, according to the National Weather Service’s latest forecast for Boise.
Boise could see a high of 92 on Sunday, rivaling a record set in 1940.
While the high will hover close to 90 on Monday, the heat could hit in earnest on Tuesday.
Tuesday is forecast to see a high of 97. Groenert said Boise saw its hottest May 12 on record in 1993, when the maximum temperature hit 94 degrees.
Boise previously set a maximum temperature record in mid-March. Baker City, Burns and Ontario, Oregon; and Jerome and McCall, Idaho, also saw record-breaking heat in the region.
Why is Boise so hot?
A high-pressure system above Idaho means dry heat and “gusty afternoon winds” across the area, according to the most recent Idaho state forecast discussion from the National Weather Service.
“The ridge will move overhead early next week, increasing temperatures to 15 to 20 degrees above normal,” the state forecast said. “No precipitation is expected through at least the middle of next week.”
If you’re looking for relief from the heat, Roaring Springs Waterpark opens for the season on Saturday, May 9, with a brand-new waterslide to explore.
After two weekends of fun, the Meridian park is set to start daily operations on Friday, May 22.
What’s the weather forecast in Boise?
Clear and sunny skies were expected in Boise on Friday, May 8, with similar conditions over the next few days, according to the weather service’s seven-day forecast.
The weather service said Boise will see a daytime high near 81 degrees before cooling down to 49 degrees overnight.
“Wind gusts combined with low humidity will locally enhance fire weather conditions where fuels have started to dry out,” the weather service said in its state forecast discussion.
On Saturday, the high will be around 79 degrees with the overnight low dropping to 48.
Sunday will see a high near 92 and an overnight low of 55 degrees.
The high on Monday will be close to 88 degrees, with an overnight low around 53.
Tuesday, May 12, will be the hottest day of the week, with temperatures climbing as high as 97. The temperature could lower to 58 degrees overnight.
On Wednesday, May 13, and Thursday, May 14, Boise will see highs in the upper 80s as the sunny weather sticks around.
How to stay cool
When temperatures are extremely high, some people’s bodies can have trouble regulating temperature.
In some cases, people can experience heat exhaustion and have muscle cramps, nausea, weakness and cold or clammy skin, according to the Centers for Disease Control and Prevention.
If heat exhaustion persists for too long, however, it can lead to heatstroke, the most serious form of heat injury. People experiencing heatstroke can have hot, red, dry or damp skin. They also can have a fast and strong pulse, and they can become confused. People should move indoors immediately and call 911 right away if they have symptoms.
If people choose to hike or be outdoors in dangerously hot temperatures, officials recommend the following tips:
- Carry and drink plenty of water and plan to replenish electrolytes.
- Eat twice as much food as normal and have salty foods on hand.
- Carry a first-aid kit.
- Pack essentials only.
- Bring a flashlight with spare batteries to hike during the cool evening.
- Spray yourself with water to cool down.
- Have a hat and sunscreen as protection from the sun.
- Have a whistle or signal for emergency use.
- Wear waterproof clothing if needed.
This story was originally published May 8, 2026 at 2:51 PM.
