Near-record heat arrived Thursday in Colorado and triple-digit temperatures will roast the state through Sunday, just in time for the official start of summer, according to the National Weather Service.

The heat wave started Thursday afternoon with the hottest temperatures in southeastern Colorado and near-record temperatures across the state, according to the National Weather Service.

Triple-digit temperatures will spread across Colorado on both Friday and Saturday, according to weather service forecasters.

The worst of the heat will span 11 a.m. Friday to 6 p.m. Saturday, forecasters said in a heat advisory.

That advisory covers Larimer, Boulder, Jefferson, Broomfield, Douglas, Denver, Adams, Arapahoe, Elbert, Weld, Morgan, Lincoln, Logan, Washington, Sedgwick and Phillips counties.

If Denver hits 100 degrees Friday, as forecast, the city will break its current June 20 record of 99 degrees, which was set in 2017, according to weather service records.

Temperatures are expected to fall just short of triple digits in Denver on Saturday, but the city is still forecast to tie its June 21 heat record of 99 degrees, the weather service said. If temperatures tip over the edge and hit 100 degrees, Denver will break its heat record two days in a row.

Triple-digit heat is relatively rare in Denver, and two-day streaks are even rarer, according to the weather service.

Denver has seen only 111 days with 100-degree weather since 1872. That’s 1.3 days each year on average.

Other cities forecast to see 100-degree weather on Friday and Saturday include Fort Morgan, Burlington, Greeley, Julesburg, Longmont, Sterling, Eads, La Junta, Lamar, Pueblo and Springfield.

Loveland is forecast for 99 degrees on Friday and 97 on Saturday, and Boulder is looking at a high of 95 on Friday and 99 on Saturday, according to the weather service.

The hottest weather on the forecast is a 106-degree high in Lamar on Friday, forecasters said.

“Heat is the leading weather-related killer in the United States, resulting in hundreds of fatalities each year,” weather service forecasters said in a hazardous weather outlook.

“Ensure that loved ones, neighbors, pets and livestock are safe from the heat.”

Cooldown scheduled for Sunday, Monday

Temperatures will cool down slightly across Colorado on Sunday, largely dropping back into the 90s, before relief arrives Monday morning, forecasters said.

In southeastern Colorado on Sunday, some cities could see a fourth straight day of 100-degree weather, including La Junta and Lamar, according to the weather service.

Rain showers and thunderstorms expected to arrive Monday will bring temperatures back down to the 70s across the Denver area and Eastern Plains, forecasters said.