Right now, there are dozens of large wildfires in the US This is where they are.

Heat wave could exacerbate California fires 1:29

(CNN) - While people in the western United States are experiencing record heat, wildfires are devastating many areas, especially in California, and red flag warnings have been issued from the northwest toward the Rocky Mountains.

There were at least 77 large wildfires burning in 15 states across the country as of Tuesday night, nearly a third of them in California, according to the National Interagency Fire Center (NIFC).

The fires have wiped out at least 262,400 acres in the 14 states where the fires are still raging, according to the NIFC.

Some 45 million people remain under some form of heat alert or warnings, and relief from the record heat in the West is not expected until the weekend.

Most of California and some surrounding areas are under an excessive heat advisory from the National Weather Service.

This is where the largest of the fires were reported as of Tuesday night, according to the NIFC, which counts area fires as complex, not individual fires. These numbers will be updated as soon as new data is available.

LEE : Death Valley, in California and Nevada, has just recorded the highest temperature on Earth

Alaska

Number of fires: Seven

Hectares burned: More than 10,500 hectares

Cause: Lightning has caused the majority of the 331 fires reported this year to date, according to the Alaska Interagency Coordination Center.

Arizona

Number of fires: 11

Size: More than 12,500 hectares

Cause: Lightning caused the largest of the fires, that of Cassadora Springs, according to information from the InciWeb Information System.

California

Number of fires: 25

Total size: More than 139,000 hectares

Cause: The August complex, made up of 20 individual fires, was caused by lightning strikes in the Mendocino National Forest, according to information from the InciWeb Information System.

LOOK : Videos show the dramatic advance of forest fires in California

Colorado

Number of fires: Five

Size: More than 54,600 hectares

Smoke covers much of Colorado and the Denver metro area is under an air quality alert.

Cause: The Pine Gulch fire, the largest now, was caused by lightning, according to an incident report on InciWeb.

Florida

Number of fires: One

Size: More than 40 hectares

Cause: Unclear

Idaho

Number of fires: Two

Size: More than 198 hectares

Cause : The cause of the Muldoon fire, which has burned approximately 162 hectares, is under investigation.

Montana

Number of fires : Three

Size: Almost 3,200 hectares

Cause: The Bear Creek Fire was caused by lightning. It has burned more than 3,000 hectares.

Nevada

Number of fires: Two that are fully contained, which means that they are no longer spreading.

Size: More than 5,600 hectares burned before being contained.

Cause: Lightning started the Poodle Fire, which has burned more than 5,500 hectares.

New Mexico

Number of fires: Two

Size: More than 1,050 hectares

Cause: Lightning also caused the Dark Canyon Fire, which burned more than 1,200 hectares.

Oregon

Number of fires: Seven, with two contents

Size: More than 8,900 hectares

Cause: The cause of the Indian Creek fire is under investigation. It has burned more than 5,600 hectares.

LOOK : PHOTOS | California burns: stunning images show devastation from upstate wildfires

South Dakota

Number of fires: One

Size: More than 200 hectares

Cause: Unclear

Texas

Number of fires: Two

Size: More than 1,600 hectares

Cause: Unclear

Utah

Number of fires: Four

Size: More than 485 hectares

Cause: Unclear

Washington

Number of fires: Six

Size: More than 17,600 hectares

Cause: The Taylor Pond Fire was caused by lightning, according to a Facebook post from the Southeast Washington Interagency Incident Management Team. It has burned almost 15,400 hectares.

Wyoming

Number of fires: 1

Size: More than 10,100 hectares

Cause: The Waddle Creek fire, on the Montana border, is still under investigation, according to CNN affiliate KULR.