A fire that erupted Monday in Southern California has prompted the evacuation of thousands of people as flames grew overnight to 2,200 acres. Gusty Santa Ana winds and low relative humidity created ideal conditions for the fire to spread, according to fire officials.

　　The Highland Fire, which was first reported in Aguanga, Calif., midday on Monday, has remained completely uncontained since it started. Evacuation orders have gradually expanded as the fire spreads. about 1,139 homes, an estimated 4,000 residents, were ordered to evacuate as of 10 p.m. Monday night, according to April Newman, a spokesperson from the Riverside Fire Department. about 489 homes, roughly 1,700 people, were under evacuation warnings. Officials had also expanded the evacuation orders to include four more areas in the region by Tuesday morning.

　　Maggie Cline De La Rosa, a spokesperson with the Riverside County Fire Department, described the blaze as a wind-driven fire, fueled by 20-30 mph gusts.

　　The Santa Ana winds are expected to continue in the area Tuesday, though the National Weather Service said the gusts would be "much weaker in areas north of San Diego County." Seasonal Santa Ana winds create dry gusts that flow from east to west in California's southern mountains, helping the spread of wildfires. The winds are often responsible for the state's most serious wildfires.

　　"When you have extreme winds with low moisture, low humidity, then that's prone to be fire weather, so that's what we're experiencing out there," Newman told The Washington Post. Despite incessant rain and heavy snowfall throughout the year, warmer temperatures dried out new vegetation and created kindling for wildfires, she said.

　　Cline De La Rosa also told local television station KTLA 5 that flames completely destroyed three structures and damaged another six.

　　Fire officials had not reported any fatalities or injuries as of Monday night.

　　Officials have set up a reception and care center at Great Oak High School in Temecula. Residents can drop off large and small animals at an animal shelter in San Jacinto, Cal Fire said.

　　California's wildfires have been relatively tame this year, burning through about 316,000 acres so far, compared with a five-year average of 1.57 million acres by this point in the year.