(Adds details on fire)
By Dan Whitcomb
LOS ANGELES, May 13 (Reuters) - More than 20,000 homes and other residences were being evacuated in and around San Diego on Tuesday as a fast-moving California wildfire driven by high winds blackened more than a square mile, fire and county officials said.
Hundreds of firefighters, assisted by water-dropping aircraft, fought to keep the flames from advancing into San Diego neighborhoods, said Lynne Tolmachoff, a spokeswoman for the California Department of Forestry and Fire Protection.
"The fire itself has been moving around in populated areas near some subdivisions so it's definitely close to many residents," she said. "They want to get those folks out of the area and into a safer area so our firefighters can get in there and do their job."
The so-called Bernardo fire comes as California enters its peak fire season in the midst of one of its worst droughts in decades, setting the stage for what state officials worry could be a particularly intense and dangerous year.
California officials have kept staffing levels for wildland firefighters at elevated levels since last year because of the drought.
No homes had been damaged or destroyed by Tuesday's fire, which erupted in the morning amid temperatures above 100 Fahrenheit (38 Celsius) and high winds, and no injuries had been reported, Tolmachoff said.
"That's the problem, we have increased temperatures, low humidity and very high winds that are fanning the flames and pushing fire along," she said.
An evacuation center was set up for displaced residents at an area high school, and several canyon roads were closed. (Reporting by Dan Whitcomb; Editing by Cynthia Johnston, Ken Wills and Lisa Shumaker)