Rim Fire at 80 Percent Containment, Quelled by Good Weather

Firefighting crews have brought the Rim Fire in California to 80 percent containment and expect to have the blaze completely under control by Sept. 20.

The blaze grew by about 1,500 acres overnight Tuesday, bringing the total number of acres burned to 237,341, roughly 370 square miles, an area larger than Chicago, New York City, San Diego or Dallas.

Firefighters credit improved weather conditions, especially a rise in overnight humidity, in aiding them battling the blaze.

A week ago the Rim Fire was only 23 percent contained, and while the fire has since expanded in size daily, fire crews have been able establish lines of control around the perimeter of the burn zone to ensure it burns no further.

Wednesday the fire's southeast flank in Yosemite National Park is expected to remain active where unburnt fuels remain between the lines of control and the fire, the west coast's fire information system InciWeb reported.

The fire's western and north flanks are considered contained, InciWeb reported.

New lines of control are being established off Tioga road -- a main east-west corridor that runs through Yosemite -- in an attempt to reduce the amount of fire operations needed to contain the fire.

Last week a local fire chief speculated that the cause of the Rim Fire was caused by an illegal marijuana-growing operation, but the U.S. Forest Service, which is the leading agency with the Rim Fire, has not announced an official cause.