After a wet month, SLO County rainfall totals well above average

December 31, 2022


Another atmospheric river is dumping rain on San Luis Obispo County, and pushing rainfall totals well above average after three years of drought.

During the past 24 hours, the storm brought between .02 of an inch in Shandon to 1.89 inches in Rocky Butte – a mountain northeast of Cambria. The storms have left many areas of the county with almost double the average amount of rainfall from July 1through Jan. 1, according to averages listed on the SLO County monthly precipitation reports.

Climate scientists track rain from July 1 through June 31. Typically, January is the wettest month in SLO County with December, February or March vying for second place.

In Templeton, the county reports the average rainfall from July 1 through Jan. 1 at 4.87 inches. Since July 1, Templeton has already received 9.35 inches of rain, almost double the average amount during those months.

Even so, the last three years were the driest on record. San Luis Obispo County remains with drought conditions ranging from moderate to extreme, according to the U.S. Drought Monitor.

Rainfall totals from July 1 through Dec. 31, along with average yearly rainfall:

Arroyo Grande – 10.01 inches to date – average 14.09 inches

Atascadero – 7.52 inches to date – average 12.06 inches

Lopez Dam – 13.52 inches to date – average 18.48 inches

Los Osos – 10.33 inches to date – average 15.77 inches

Nipomo – 7.31 inches to date – average 12.62 inches

Oceano – 8.77 inches to date – average 12.26 inches

Rocky Butte – 31.51 inches to date – average 34.75 inches

San Luis Obispo – 8.34 inches to date – average 16.82 inches

San Simeon – 10.97 inches to date – average 15.12 inches

Santa Margarita – 12.03 inches to date – average 16.96 inches

Shandon – 6.32 inches to date – average 8.44 inches

Templeton – 9.35 inches to date – average 13.05 inches

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Great, now we can start building thousands of new houses!

Exactly, more “affordable” $700k-$800k “ work force housing”

California and the west in general, has been drier than usual for the last 10 years. Good news for the southwest late Spring and into next rainy season. La Nina (drier winter) is forecast to be replaced by a moderate to strong El Nino (above average rainfall) as it looks now. The state, counties, and municipalities should start preparing now.

I wish they would have prepared while reservoir levels were low enough to improve and raise dams, and build new ones. Having above average rain, means nothing when we have less than average storage.

“Climate scientists track rain from July 1 through June 31.”

Them scientists must be pretty smart to add a heretofore unknown 31st day to the month of June.

The National Weather Service in Oxnard, who oversees our forecast area, Records rainfall totals from October 1st – September 30th as our rainfall year locally. This was somewhat a recent change a few years back.