The fire, which began in Waldo Canyon over the weekend and has destroyed more than 15,000 acres (6,070 hectares), careened into the Colorado Springs community of Mountain Shadows on Tuesday, doubling in size overnight and setting alight the mountains that rim the city.
With the inferno -- one of several in the US west -- showing little sign of abating, the White House announced that Obama would visit Colorado Friday.
In phone calls Wednesday with Colorado Governor John Hickenlooper and Colorado Springs Mayor Steve Bach, Obama expressed his concern about the extent of the damage and "informed both that his thoughts and prayers are with responders and families impacted by these and other fires burning across the western United States," a statement said.
Another fire raging about 60 miles northwest of Denver -- described by the Denver Post as Colorado's second-largest in history -- has eaten through 87,284 acres. That blaze, known as the High Park Fire, which was ignited by lightning, is now 65 percent contained.
Firefighters are also working to keep the Flagstaff Fire -- estimated at just over 200 acres -- away from the city of Boulder, home to the University of Colorado.
Several more blazes are scorching other parts of the state, including one dubbed the Little Sand Fire, located 13 miles northwest of Pagosa Springs that was sparked by lightning on May 13th and has burned through 22,440 acres of land.
Among the areas threatened by the Waldo Canyon fire was the US Air Force Academy, which evacuated two housing areas, a day before the scheduled arrival of 1,000 new cadets, the academy said.
Officials declined to estimate the number of homes destroyed in the fire's wake, but feared the figure would be high.
Owners of the Flying W Ranch, a working cattle ranch known nationally for its western-style restaurant, said on their website that it had been "burned to the ground."
Soaring temperatures have compounded the agony for teams battling the blaze, which is estimated to be only five percent contained and has spread quickly since it began on Saturday.
Turbulent winds on Tuesday afternoon prompted authorities to seek evacuations of up to 32,000 residents, with that number rising to 36,000 on Wednesday, Hickenlooper told broadcaster CNN.
There were no immediate reports of deaths or injuries.
The winds became an issue again late Wednesday, with Fire Incident Commander Rich Harvey telling reporters there was concern the wind was pushing the flames toward Colorado Springs, which was already enveloped by a heavy plume of smoke.
"The wind is kicking up and it's causing us problems," Harvey said.
It was not immediately clear what sparked the initial flames but Hickenlooper, who raced to the scene Tuesday night, suggested it was not lightning.
"There's suspicion out there that we've got some idiot," he told CNN. "We're working as hard as we can to approach and get the real facts and not jump to conclusions."
The Federal Bureau of Investigation's Denver division said it was helping local, state and federal law enforcement to determine "if any of the wild land fires resulted from criminal activity."
Record high temperatures, extremely low humidity and wind gusts of up to 60 miles an hour have fueled blazes across the American West. Tinder-like conditions were created by this year's unusually mild and dry winter, officials said.
"It's just like the perfect storm for fires," Hickenlooper said.
Four US Defense Department C-130 aircraft were assisting local teams to contain the blazes, airlifting water and retardant.
As of Wednesday morning, they had carried out 23 so-called air drops over the Waldo Canyon fire, and five air drops over the Flagstaff Fire, a statement said. The National Guard has also been mobilized to help in the efforts.
The state of Utah also is combating a major fire, which burned through more than 6,000 acres of grassland in an area about 45 minutes south of Salt Lake City.
More than 8,400 people, 578 fire trucks and 79 helicopters have been deployed to tackle wildfires around the United States, the White House said.
Colorado is considered a swing state in the upcoming presidential elections, meaning that neither Obama nor his presumed Republican rival Mitt Romney can be guaranteed a victory there.