Pocatello experienced record heat both on Sunday and Monday, at the start of a prolonged heatwave that should bring record temperatures throughout the West through mid-June, according to the National Weather Service and AccuWeather meteorologists.

On Sunday, the local temperature reached 100 degrees at about 5 p.m., topping the prior record for June 13 set in 1940, when the temperature reached 95 degrees.

The high temperature on Monday was 99 degrees, a degree higher than the record for June 14 set in 1974.

“We’re looking to get a little bit cooler over the next couple of days,” said National Weather Service meteorologist Jeremy Schulz.

Other western locations are poised to set all-time highs for the month. The National Weather Service has issued excessive heat watches and warnings effective until June 18 throughout California, southern Nevada, western and southern Arizona and Utah.

Record temperatures have also been recorded in Idaho Falls and Stanley, where temperatures more customary for July and August have been reported.

“The heat will only become more intense through the week,” AccuWeather meteorologist Mary Gilbert said in a press release.

Salt Lake City broke a record on Sunday dating all the way back to 1918, with temperatures reaching 102 degrees, according to AccuWeather. AccuWeather meteorologists predict Salt Lake City will tie or break its record highs each day through Wednesday, with highs exceeding 100 degrees.

“No easy way to say this, so we’ll just cut straight to the chase: It’s going to be very hot for a long time this week,” the National Weather Service office in Salt Lake City said on Twitter, according to the AccuWeather press release.

The National Weather Service described the weather in Phoenix, where the temperature was above 110 degrees on Saturday, as “rare, dangerous and deadly.”

Las Vegas could reach a record 115 degrees from Tuesday through Thursday.

“It is unusual for Las Vegas to reach above 115 degrees, even in the hottest part of summer,” Gilbert said in the press release.

Thunderstorms this week in Wyoming, Colorado, New Mexico, Utah and Arizona could bring lightning that could further elevate the fire risk, according to AccuWeather.