Temperature records tumble as heat wave settles in

Three boys played with a sprinkler head in the park area in front of the California Academy of Sciences Tuesday May 13, 2014 in San Francisco, Calif. Hot weather returned to the Bay Area and visitors to Golden Gate park did their best to stay cool. less Three boys played with a sprinkler head in the park area in front of the California Academy of Sciences Tuesday May 13, 2014 in San Francisco, Calif. Hot weather returned to the Bay Area and visitors to Golden ... more Photo: Brant Ward, The Chronicle Buy photo Photo: Brant Ward, The Chronicle Image 1 of / 28 Caption Close Temperature records tumble as heat wave settles in 1 / 28 Back to Gallery

(05-13) 15:54 PDT SAN FRANCISCO -- Hot-weather records fell around the Bay Area on Tuesday as a ridge of high pressure pushed temperatures into the 90s in many locations, the National Weather Service said.

In downtown San Francisco, the thermometer reached 90 around 3:30 p.m., breaking the record for the date of 87 degrees set in 1927, said weather service forecaster Austin Cross.

The mid-afternoon temperature at Oakland International Airport hit 89 degrees, surpassing the 1972 high for the date by a single degree. At Moffett Field in Mountain View, it was 91 degrees, tied for the record set in 1972.

More records where broken farther south. It was 89 at the Monterey airport, eclipsing the 1976 mark for the date of 87, and Salinas sweltered in 94-degree heat, also a new record.

Hottest of all, however, was Reed-Hillview Airport in San Jose, where the thermometer peaked at 97 - two degrees shy of the record for a May 13, Cross said.

While Tuesday was hot, Wednesday is predicted to be the real scorcher, with temperatures in such hot spots as the Livermore Valley predicted to be well into triple digits.

"We're looking at fried grapes on the vine," said weather service forecaster Diana Henderson. "Even going to the coast won't provide any real relief."

The heat brings with it real danger for children, outdoor workers, pets and the elderly, Henderson said.

"Extra attention should be paid to neighbors and kids or pets in cars," she said. "We're telling everyone to take it slow and stay hydrated."

Bay Area air quality officials declared the third consecutive Spare the Air Day for Wednesday and asked people to carpool or take public transit and avoid using gas-powered gardening tools.

A slow cooling trend will begin Thursday, but temperatures won't return to seasonal norms until the weekend, Henderson said.