Hundreds of households in the historic New Mexico city of Las Vegas have been asked to evacuate immediately on Monday as intense winds and bone-dry conditions fueled a huge wildfire burning on the outskirts of town.

The blaze, dubbed the Calf Canyon Wildfire, had scorched more than 103,000 acres, or more than half the area of New York City, as of Monday morning, according to U.S. Forest Service officials in New Mexico.

It was 30% contained as of Monday as it burned drought-parched vegetation northwest of the city of 13,000 people.

The fire, the largest active U.S. wildfire, is the most destructive of a dozen blazes in the Southwest that scientists say are more widespread and arriving earlier this year due to climate change.

"It is extremely smoked out here. Lots of smoke and falling ash," Jesus Romero, the deputy county manager of San Miguel County, told Reuters in an interview. "The winds are starting to pick up now and we are starting to get a lot more wind."

Forecasters issued a red flag warning, signaling that fires could start and spread easily, for the area where winds of 50 mph (80.4 kph) and humidity as low as 5% were expected through Monday.

Several hundred households in the northwestern corner of the city were told to evacuate immediately on Monday morning, San Miguel County said in an alert.

"This emerging situation remains extremely serious and refusal to evacuate could be a fatal decision," the county said. Another 4,000 to 5,000 people have been told to be ready to evacuate immediately.

Crews bulldozed fire breaks to the north and west of the historic university town to protect ranches, rural houses and the United World College.

The residents of nearby communities of Ledoux, Mora and Cleveland were told to evacuate on Sunday as strong wind gusts drove the fire near their mountain valley communities.

Burning since April 6, the fire has destroyed hundreds of properties and forced the evacuation of dozens of settlements in the Sangre de Cristo Mountains, but has yet to claim a life.