The Canyon Fire was described as a "vegetation fire" by the Orange County Fire Authority.
The Corona Fire Department on Monday night tweeted that the fire was up to 2,000 acres and 5% contained.
Winds Monday night and Tuesday morning were expected to blow mainly from the northeast, potentially bringing smoke and ash into Villa Park, Orange, Anaheim and Yorba Linda.
The Corona Fire Department said evacuations were being requested for about a dozen streets.
Evacuations were in place for about 300 homes in the Dominguez Ranch area, with residents invited to take shelter at Corona High School.
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KNTV reports that the fire in the Oakland Hills neighborhood had grown quickly to about 20 acres in under an hour, or roughly a third of a square mile.
Overnight, five helicopters with night-vision and three planes tried combating the wildfire from above.
Additionally, crews were setting backfires, hoping to keep the fire from crossing the freeway. Dominguez Ranch Road in Corona was closed to incoming traffic at Green River Road.
Authorities ordered residents of all homes south of Green River Road - from the 91 Freeway to Trudy Lane, including the Orchard Glen Tract - to leave as more than 300 firefighters trudged through steep, rugged terrain.
The fire prompted the Corona Norco Unified School District to cancel classes today at four schools - Coronita Elementary School, John Adams Elementary School, Cesar Chavez Academy and Prado View Elementary School - due to active evacuations, road closures and poor air quality, district officials announced on Facebook. "But we're asking the public, if possible, to avoid the eastbound 91".