Weather Watch

It’s cold, but not a record. Here are the Central Coast’s most extreme temperatures.

Ice forms on tree limbs in Los Osos on Jan. 14, 2007.
Ice forms on tree limbs in Los Osos on Jan. 14, 2007.

If you’re a weather geek like me, you’ll probably find temperature records fascinating. I’ve put together some local all-time high and low temperatures and the reasons behind them in this week’s column.

If you have any disputes or interesting facts to share, please email me.

In the first week of October 1987, a strong, high-pressure ridge combined with Santa Lucia (northeasterly) winds to produce a scorching heat wave across California. San Luis Obispo was the warmest location in the nation, with 111 degree temperatures recorded at the airport two days in a row. The Santa Maria Public Airport reached its all-time high temperature of 108 degrees Oct. 4. Lompoc hit 110, breaking that location’s all-time high. Because of the warm overnight conditions, many of the Cal Poly dorms warmed up like large brick ovens and forced some students to sleep outside — including myself.

For San Luis Obispo, the official record-high temperature is 112 degrees, set Sept. 14, 1971. However, on June 20, 2008, a mesoscale high-pressure system moved just east of San Luis Obispo and combined with a warm, upper-atmosphere, high-pressure ridge over California, producing persistent Santa Lucia (offshore) winds that descended the Cuesta Grade and created compressive heating. As the longest day of the year emerged, the mercury soared to 114 degrees at the PG&E meteorological tower at Los Osos Valley Road and Foothill Boulevard. Hot indeed!

The highest temperature ever recorded in the United States occurred at Furnace Creek in Death Valley on July 10, 1913, when the temperature hit 134 degrees. However, for many decades a story persisted that Santa Barbara was believed to have reached 133 on June 17, 1859, because of compressive heating as gale-force (sundowner) winds sloped down the Santa Ynez Mountains.

A U.S. Coast Survey crew was reported to be at sea off the coast of Santa Barbara at the time and supposedly recorded the 133 temperature. Fruit fell to the ground and birds dropped from the sky, according to personal accounts. That report has since been rebuked by numerous historians.

Some of the lowest temperatures ever recorded along the Central Coast occurred Dec. 22 and 23, 1990. A strong, southerly flowing jet stream moved a cold Arctic air mass from Western Canada — the so-called Yukon Express — down the West Coast. The sky turned overcast, which gave an ash-gray hue to the mountains. The meteorological tower at Diablo Canyon nuclear power plant reported cold, northerly winds of 35 mph, with sustained gusts reaching 45 mph.

The temperatures dropped to the mid-30s along the shoreline. By Dec. 22, the temperature hit the freezing point for the first time at Diablo Canyon since 1976, when the plant started keeping weather records. It was cold throughout the western United States — Denver reported 20 degrees below zero, while Wild Reservoir north of Elko, Nevada, plunged to 31 degrees below.

Gary Ryan, who was a meteorologist with the National Weather Service in Santa Maria, confirmed record-breaking low temperatures on Dec. 22 and 23 throughout San Luis Obispo and Santa Barbara counties. The Paso Robles Municipal Airport reported an all-time low of 8 degrees. San Luis Obispo dropped to 17 degrees. (Note: Supposedly the lowest temperature ever recorded for San Luis Obispo occurred Dec. 13, 1987, when the mercury plunged to 12 degrees, but my records don’t match up with that report.)

The temperature dropped to 20 degrees in Lompoc, its lowest temperature on record, while Santa Maria reached 21 degrees. Surprisingly, this was not the lowest temperature ever recorded for that location; Santa Maria reached 20 degrees on Dec. 7, 1978. The region’s avocado crop was hit hard, and numerous water pipes burst. Plumbers were kept busy for days afterward repairing pipes and fixtures. Many local hardware stores sold out of plastic and copper pipe. Freezing winds blew through the Salinas Valley and killed or severely damaged many eucalyptus trees along Highway 101. This was considered a once-in-a-100-year event.

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John Lindsey’s column is special to The Tribune. He is PG&E’s Diablo Canyon marine meteorologist and a media relations representative. Email him at or follow him on Twitter: @PGE_John.