Oklahoma is under alert for fire danger on Monday after being devastated by deadly blazes over the weekend, and amid a continued fire threat in the Plains.

More than 40 million Americans are under alert for fire weather conditions over the next few days. Red flag warnings have been issued from Texas to South Dakota for critical to extreme fire danger due to the chance for high winds and low humidity.

Parts of Oklahoma, as well as Colorado, Kansas, New Mexico and Texas, face a critical threat of fire danger, with gusts up to 45 mph possible along with very low humidity.

Amid the threat, a “dangerous” wildfire ignited in southeast Guthrie, Oklahoma, the U.S. National Weather Service in Norman said Monday afternoon while urging residents in the area to evacuate immediately.

The continued fire threat comes after four people were killed and over 140 injured in Oklahoma due to high winds and raging wildfires that ignited on Friday, officials said.

More than 130 fires were reported in 44 counties, the Oklahoma Department of Emergency Management said Friday.

More than 400 homes and structures have been damaged in the fires, the agency said. That includes Oklahoma Gov. Kevin Stitt’s ranch near Luther; the governor said his farmhouse experienced a “total loss” in Friday’s fires.

“We’ll be rebuilding with all of Oklahoma,” he said in a video posted to social media over the weekend.

Stillwater Fire Chief Terry Essary told ABC News on Monday that 75 structures were lost in his area alone after multiple wildfires broke out on Friday amid high winds that made for challenging conditions.

“The wind was blowing so hard,” Essary said. “It was a very helpless feeling, but you just keep at it. You do what you can, you save what you can, and you keep moving on to the next and helping as many people as possible.”

A state of emergency remained in effect on Sunday for 12 Oklahoma counties due to the wildfires and fire weather conditions, the Oklahoma Department of Emergency Management said.

On Tuesday, the fire threat continues in Oklahoma and increases for parts of the Texas Panhandle and southeastern New Mexico, where there will be an extreme critical risk for fire weather conditions. Winds could gust 50 to 75 mph combined with very low humidity and dry fuels. Any fires that develop in these conditions can spread easily and will be very difficult to control.

ABC News’ Mireya Villarreal and James Scholz contributed to this report.