Sacramento is on track for a rain-free February. How rare are dry winter months?
Zilch.
With just 11 days left in a leap-year edition of February, that’s how much precipitation the city of Sacramento has received for the month: 0.00 inches of rain.
That mark would, obviously, be a record low if it stands, breaking a mark set 121 years ago. And with 5-day, 10-day and longer-term forecasts from the National Weather Service and other agencies predicting warm, sunny days with no rain in sight, it seems Sacramento may be on the way to its first ever bone-dry February.
Sacramento’s previous driest February ever recorded saw 0.04 inches of rainfall, weather service forecaster Michelle Mead told The Sacramento Bee earlier this month. That minuscule mark came in 1899.
“Let’s do a rain dance!” the agency’s Sacramento office wrote in a tweet Tuesday night that noted there has never been a completely dry February since official records began in 1849.
A chart by the weather service of monthly rain totals dating back to 1941 shows that we’ve gotten less than a quarter-inch of rain just three times since the end of World War II: 0.2 inches in both 1995 and 1953, and 0.15 inches in 1964.
How much rain is typical for February?
Over the last 80 years, Sacramento’s average rain total for February is 3.10 inches, behind January’s figure of 3.57 and just ahead of December’s 3.06.
Rainfall for February has been something of a roller coaster in recent years. Compared to this ongoing month, last year was a deluge. February 2019 had multiple atmospheric river storms pass through Northern California, drenching the Sacramento Valley and helping the capital city total 7.84 inches for the month. For the math fans out there, that’s 196 times more precipitation than the 1899 record low.
Before 2019’s soaking, February 2018 barely got more than half-inch – 0.60. The year before that, February 2017 saw a downpour of 8.25 inches amid the same systems that brought devastating floods to Northern California.
Even in peak California drought years, February’s rain totals bounced around: in 2016, back down to 0.82 inches; in 2015, 2.82 inches; in 2014, 4.14 inches; and back in 2013, only 0.36 inches.
How rare is a month of no rain, outside of summer?
Although a total lack of rain would be a first for Sacramento in February, it has happened before in every other month except January, March and November going back to 1941, according to NWS data. The March low of 0.05 inches was set in 2008. The minimums for January (2015) and November (1995) are “trace” amounts, which means the totals measured at the NWS station at Sacramento Executive Airport were negligible, but water did indeed fall from the sky.
There have been seven rain-free month outside of June, July or August since 2000, all Septembers and Octobers. The most recent one was four months ago in October. Prior to that, Sacramento got no rain in October of 2013 and 2002, and in September of 2008, 2006 and 2002.
A rainless month before June is even rarer for the City of Trees, happening just twice since 1941, in April 1949 and May 1976.
What’s causing the lack of rain?
A high-pressure ridge that’s staying stagnant over the Pacific is keeping wet weather away from California, as UCLA climate scientist Daniel Swain explained last week.
The same weather pattern contributed to California’s five-year drought last decade.
What about the rest of Northern California?
It’s not just Sacramento that’s gone dry this month. Fresno, Modesto, Stockton and Redding were all barren through Wednesday morning, according to the NWS.
It’s even been dry on the coast. The Eureka area, for example, has had just over a half-inch of rain fall this month, against a historical norm of more than 5½ inches.
As for what this lack of precipitation means, the bad news is that poor rain totals this winter could set up a more active wildfire season later in 2020, as climate experts told The Bee earlier this month.
The good news, given how wet the start of 2019 was, is that it usually takes multiple dry winters to bring on a full-blown drought.
This story was originally published February 19, 2020 at 7:18 AM.
