High Humidity, Temperatures Add Up to Misery

By JACK LEONARD and ERIC MALNIC

Sept. 5, 1997 12 AM PT

TIMES STAFF WRITERS

The thermometer climbed to a sticky 98 degrees at the Los Angeles Civic Center on Thursday, but it felt more like 102--not enough to prompt an excessive heat warning, but more than enough to make anyone outside miserable.

“It’s unbearable,” said Olga Quezada as she paused to buy a hot dog from a stand on the blistering sidewalk of Grand Avenue atop Bunker Hill.

The vendor, Alfredo Garcia, had a different complaint--although drink sales were up, the heat was cutting into his hot dog sales.

“When it’s hot, people don’t eat much,” he said.

The reason it felt hotter than the numbers on the thermometer Thursday was the relative humidity, which hovered at a rather moist 33% when temperatures peaked about 1 p.m.

Relative humidity readings reflect the amount of water vapor in the air, compared to what the air could retain if saturated. The capacity of air to retain moisture varies with temperature and barometric pressure. The hotter it is, and the lower the pressure--as in the case of a major storm--the more water air can hold.

On Thursday, the combination of a 98-degree temperature and 33% humidity created a “heat index” of 102 at the Civic Center.

It was a lot worse in the San Fernando and San Gabriel valleys. In Van Nuys, for example, a midafternoon temperature of 106, coupled with relative humidity of 32%, generated a heat index of 112 and prompted an excessive heat warning.

The National Weather Service said such heat warnings are issued whenever the index reaches 105 in downtown Los Angeles and the coastal valleys of Southern California. The warning advises people to avoid direct sunlight, drink plenty of water and remain in air-conditioned places when possible.

For wrecking crews demolishing a building at Broadway and 4th Street, it wasn’t possible.

“It’s kind of nice all summer and then we get this miserable weather,” said Jason Babcock, who took a brief break while waiting for a rubbish truck to arrive at the construction site.

He said that for the men working under the plastic sheeting that wraps the outside of the building to protect the street from dust, the heat and humidity were stifling.

Home, he said, has offered little relief recently. He has a small air conditioner that doesn’t work very well when the humidity is high, but even that’s better than nothing.

“You’d be dead if you didn’t have an air conditioner after working here all day,” Babcock said. “You’ve got to go home at night and recuperate.”

In the San Fernando Valley, Pierce College student Keith Fraser walked around the campus Thursday with an electric fan and an extension cord. He said he carried the fan from class to class and plugged it in to keep cool.

“Nobody seems to mind,” he said.

Forecasters said temperatures should abate somewhat today, with highs in the mid-90s in the valleys and a top reading of about 93 at the Civic Center. Perhaps more important, the relative humidity should also drop.

For most of us that’s good news, but Elia Tucker and Zara Rocke had different perspectives on the weather as they trudged up the Grand Avenue grade in downtown Los Angeles.

“It’s humid,” said Rocke, a native Southern Californian.

“No. It’s dry,” said Tucker, a native of tropical Belize.

As the National Weather Service says, humidity is relative.

Times staff writer Solomon Moore contributed to this story.

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

The Heat Index

High air temperature coupled with high humidity can make it feel hotter than it really is.

*25, *30, *35 *40 *45 *50 *55 *60 *65 *70

**125: ***0 ***0 ***0 ***0 ***0 ***0 ***0 ***0 ***0 ***0

**120: ***139 ***148 ***0 ***0 ***0 ***0 ***0 ***0 ***0 ***0

**115: ***127 ***135 ***143 ***151 ***0 ***0 ***0 ***0/0/0

**110: ***117 ***123 ***130 ***137 ***143 ***150 ***0 ***0 ***0 ***0