Santa Ana winds swept through parts of Southern California on Friday, closing a state college campus as a high-pressure system brought continuing hot, dry weather and extreme fire danger.
California State University, San Bernardino, stopped classes at midmorning as a precaution, affecting some 17,000 students, spokesman Joe Gutierrez said.
"We've had wind damage in the past where it knocked down a tree or a limb," he said.
There were no immediate reports of wind damage but the campus weather station recorded sustained winds of 32-48 mph with gusts of 51 mph early Friday morning, according to a school statement.
Gutierrez said students received warnings by emails, text, voicemails and Facebook messages to stay home or leave as soon as possible.
"If you're in class, stay in class, you're safer indoors. But once your class is over, leave immediately," Gutierrez said.
The 441-acre campus sits at the foot of the San Bernardino Mountains and is often swept by the hot, dry Santa Ana winds that roll downslope and through canyons. Some buildings have permanent windbreaks.
"The Santa Anas are always here. Always," Gutierrez said.
The hot, dry weather prompted the National Weather Service to issue red-flag warnings through Saturday afternoon for mountains and valleys.
Winds are expected to strengthen overnight from Friday to Saturday, with peak winds expected to reach 70 mph in the mountains and 55 mph across coastal and valley areas.
Despite recent rains, low humidity has left brush dry and vulnerable to fire.
In Riverside County, extra fire engines were stationed in some areas.
The weather service also warned of high surf, reaching 8 feet in the Los Angeles area Friday night and up to 14 feet farther north.