Two wildfires burning in the western United States — including one that has become a “megafire” on the North Rim of the Grand Canyon — are so hot that they are spurring the formation of “fire clouds” that can create their own erratic weather systems.

Wildfires burning at the Grand Canyon and in Utah are so hot that they're spurring the formation of "fire clouds" that can create their own erratic weather systems.

A fierce blaze that has burned along the Grand Canyon's North Rim since being sparked by lightning on July 4 has exploded in size in recent days, reaching "megafire" status and becoming the largest wildfire in the U.