Boise just broke a century-old temperature record. Here’s how hot it got
Boise broke a temperature record that’s more than a century old on Wednesday, March 18 — with a weather feat that has only happened twice in the city’s recorded history.
The temperature in the City of Trees reached 80 degrees at 4:36 p.m. Wednesday, the National Weather Service in Boise posted on X, shattering the previous record for the date.
What’s more, the weather service said, it was only the second time Boise has experienced 80-degree weather in winter. The other occurrence was March 19, 1997.
That means Wednesday was the earliest recorded 80-degree day in Boise history, with records dating to 1875.
The previous maximum temperature record for the date was set on March 18, 1910, according to the weather service. The mercury hit a high of 74 degrees that day.
That summer, Idaho experienced “possibly the largest wildfire in modern American history,” Boise State News reported. The Great Fire of 1910, also known as the Big Burn, scorched 3 million acres and killed 87 people.
Will Boise temperatures break more records?
Boise is expected to see record-setting highs due to a heat wave that’s sweeping the West Coast.
On Wednesday, Boise was expected to see a high of 76 degrees, the weather service said in an X post that morning. The eventual high was well beyond that.
The high could reach 79 degrees in Boise on Friday, potentially breaking a maximum temperature record set in 1877, according to the weather service.
Boise could also set a record for the warmest low temperature on Friday, the weather service said.
On that day, the low temperature is expected to be 51 degrees — three degrees higher than on March 20, 2017, when the low hit 48 degrees.
According to the weather service, Boise could also break a warm low temperature record on Saturday. The weather agency forecast a low of 51, compared to 47 degrees on March 21, 2024.
How long will the heat wave last?
“A strong cold front” is expected to arrive in Idaho over the weekend, signaling that a “return to mostly dry conditions is expected,” the National Weather Service said in its most recent Idaho state forecast discussion.
“Windy, cooler, and wet weather will return by mid-week,” the weather service said in its forecast.
On Sunday, Boise is expected to see a high of 61 degrees — 18 degrees cooler than the high forecast on Friday — and a low around 40, according to the weather service’s latest seven-day forecast.
This story was originally published March 18, 2026 at 5:31 PM.
