Steamy Heat Drops Into Fall

The heat is off.

After gasping and sweating through the third warmest August in the 121-year record, Los Angeles residents can brag they survived and gratefully welcome a refreshingly cool fall, which officially began Tuesday night.

Because of a high pressure system that remained trapped over Southern California in July and August, the summer of 1998 was marked by record-breaking temperatures at the Los Angeles Civic Center and throughout the San Fernando Valley.

Chatsworth, one of the hottest spots in the Valley, not only broke seven records for high temperature but also rewrote the book for the hottest day in the month of August. That occurred on Aug. 29, when the mercury hit 113 degrees and surpassed the Aug. 23, 1985 record high of 112.

The most memorable day at the Los Angeles Civic Center was Aug. 31, said Stuart Seto, a weather specialist for the National Weather Service in Oxnard. On that date, Los Angeles broke the record for the hottest minimum temperature with a low of 76 degrees. That beat the record set at the Civic Center in 1995, when the low was 73 degrees.

“Besides the high pressure, another effect was that offshore winds were strong enough to block the afternoon sea breeze from breaking through the heat and providing relief,” Seto said.

According to WeatherData, which provides weather information to The Times, the average temperature for the month of August was 79.9 degrees at the Los Angeles Civic Center, making it the third warmest August on record. August 1983 was the hottest with an average of 80.8 degrees; second was August 1994 with an average of 80.5 degrees.

Blame big city growth. Urban areas are staying hotter for longer periods because the increasing numbers of tall buildings block the flow of cooling breezes, said Steve Pryor of WeatherData.

For that reason, most of the record-breaking temperatures are being set in the 1990s, he said.

Marking an official escape from summer’s heat, fall officially began Tuesday at 10:37 p.m. PDT.

Seto of the National Weather Service said the outlook for the next few months is unclear. The weather phenomenon known as La Nina--sister to last winter’s rainy El Nino but characterized by cool, dry conditions--is waiting in the wings, but it is too early to tell how strong it will be, Seto said.

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One Hot Summer

Record-breaking temperatures of summer 1998:

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Chatsworth Old record Date Temp. and year July 16 108* 102* (1980) Aug. 4 109 103 (1969) Aug. 22 108 107 (1972) Aug. 23 111 108 (1991) Aug. 29 113 110 (1985) Aug. 30 112 110 (1995) Aug. 31 108 106 (1985) Lancaster July 27 108 107 (1980) Aug. 4 109 108 (1966) Burbank July 16 103 102 (1936) Los Angeles Civic Center July 17 98 97 (1925) Aug. 9 100 98 (1935) Aug. 30 101 100 (1967)

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Source: National Weather Service, WeatherData