Has it ever snowed in SLO County on Christmas? Is it possible? Here’s what experts say

It’s a scene straight out of a Hallmark holiday movie.

You wake up on Christmas morning to find your front yard blanketed with white snow piled high on your driveway as icicles dangle from the roof.

But has San Luis Obispo County ever had a white Christmas? Is it even possible for the area to see snow on Dec. 25?

Has it ever snowed in SLO County on Christmas Day?

The short answer is no, according to John Lindsey, a retired PG&E marine meteorologist.

“As far as I know, we’ve never had a white Christmas,” Lindsey said.

According to the National Weather Service, a white Christmas is defined as at least 1 inch of snow on the ground on the morning of Dec. 25.

However, no measurable snowfall has been recorded on the holiday in the region since 1870, Lindsey said, based on local weather data. Snowfall is measurable when there is at least one-tenth of an inch on the ground.

Lindsey said the closest SLO County has come to a Christmas snowfall was when a powerful storm swept into Central California on Dec. 15, 1988 — closing the Cuesta Grade north of San Luis Obispo, shuttering schools and stranding travelers.

The North County saw record amounts of snow, ranging from 5 to 8 inches, with Santa Margarita receiving a whopping 7 inches.

Snow is a rarity in December in SLO County.

On average, Cal Poly in San Luis Obispo received zero inches of snow in December from 1893 to 2016, according to a climate summary from the Western Regional Climate Center.

The city of Paso Robles recorded a scant 0.1 inches of snow on average from 1894 to 2016, a separate climate summary said.

Is a white Christmas possible in SLO County?

“We could totally have a white Christmas,” Lindsey said.

However, he added, a few factors make snow sparse in SLO County during the holiday season.

For starters, winter tends to be relatively mild in the region due to its proximity to the Pacific Ocean, Lindsey said, with temperatures rarely dropping below freezing.

“The ocean has a tremendous influence in our area,” he explained. “During the winter, it keeps us warmer. During the summer, it keeps us cooler.”

Although clear skies can mean cooler temperatures, Lindsey said, the mercury rises when clouds roll in.

“Before it snows or rains, it gets warmer,” he said, so the white stuff rarely sticks around for long.

December also tends to be fairly dry compared to the rest of the winter months, which means there’s less precipitation available to transform into white fluffy flakes.

On average, Cal Poly recorded 4.01 inches of rain in December from 1893 to 2016, Western Regional Climate Center data showed, compared to an average of 4.96 inches in January.

During roughly the same time period, Paso Robles received an average of 2.56 inches of rain in December and 3.46 inches of rain on average in January, the center said.

When has SLO County gotten significant snow?

According to Tribune archives, snow has been spotted on the Central Coast several times over the past century or so.

In 1910, the area experienced what the San Luis Obispo Tribune described as the “heaviest snow storm since 1885.”

Photos from 1922 show snow on the ground in Monterey Street in downtown San Luis Obispo.

In February 1944, local residents drove up the Cuesta Grade to have a snowball fight, Tribune photographer David Middlecamp wrote in a 2019 “Photos from the Vault” column

Shandon got almost 4 inches of snow in December 1967, when chains were required to drive between Morro Bay and Atascadero, Middlecamp said.

In March 1976, a storm topped local hillsides with snow, closing the Cuesta Grade to Highway 101 traffic and forcing the Goodyear blimp to land at the San Luis Obispo County Regional Airport.

Snow also closed the Cuesta Grade in March 1991.

In February 2019, a chilly low-pressure system led to low snow levels throughout the Central Coast.

Most recently, a storm dropped snow across the higher elevations of SLO County in February, dusting vineyards in Paso Robles, frosting fields off Highway 58 and providing a dramatic backdrop for surfers competing in the SLO CAL Open in Morro Bay.

Caltrans closed parts of Highway 41 and Highway 58 due to the wintry weather.

What are the weather conditions needed to produce snow?

Lindsey described the ideal weather conditions to produce precipitation in SLO County.

“You need a pretty vigorous upper-level, low-pressure system” coming out the Yukon territory in Canada and traveling down through Washington state, Oregon and Northern California to reach the Central Coast, he said.

The system “pulls that cold air mass from the upper levels of the earth’s atmosphere to the earth’s surface,” Lindsey said.

When the two air masses collide, the warmer body of air gets colder and reaches its dew point, he said, resulting in condensation.

“That’s how rain is generated,” he said, as well as snow, sleet and graupel — granular snow pellets also know as soft hail.

Lindsey said that 75 to 85% of local rainfall is coming from southern winds bringing up warmer air into SLO County.

“You have a cold front that stretches all the way past Hawaii. That front is dragging up all that warm, moist subtropical air toward California,” Lindsey said. “It has such a high dew point ... that it presents tremendous amounts of rain.”

Where are you most likely to see snow on the Central Coast?

According to Lindsey, you’re most likely to see snow at higher elevations on the Central Coast.

For every 1,000 feet of elevation, the air temperature drops by 5.5 degrees, Lindsey said, unless it’s raining. Then, the temperature drops by 3.2 degrees.

“That’s why you get more snow on the mountains,” he explained.

The highest elevation in San Luis Obispo County is Caliente Mountain northwest of New Cuyama at 5,106 feet. In Santa Barbara County, the highest elevation is Big Pine Mountain at 6,828 feet.

Local roads that offer the best views of snow include Highway 58 east of the California Valley, which has a summit of 3,528 feet, and Highway 166, which summits at Reyes Station at 2,968 feet.

Highway 33 crests at 5,000 feet near Pine Mountain leading into Los Padres National Forest.

You could see snow on Highway 101 at the Cuesta Grade at 1,522 feet, Lindsey said, but you have a better chance on Highway 46 on the Antelope Grade at 1,765 feet.

“Who doesn’t want a white Christmas?” Lindsey asked. “It would be romantic to get snow. It’d be lovely on Christmas Eve and Christmas Day — but you talk to anyone who’s spent any time in the snow and (they’ll tell you) it gets really old really quick.”