Driest First Quarter of Year on Record for Much of California

Driest First Quarter of Year on Record for Much of California

There was no ‘miracle March’ for rain lovers in California this year following an exceptionally dry January and February. The dry weather continued through March resulting in the driest first three months of the year on record for San Francisco and other sites across the state.

San Francisco received a March total of .96” with half this amount falling on the last day of the month (Sunday March 31st). This brought the 3-month total (since January 1st) to 2.30”, just 19% of normal (normal amount for the period is 12.22”) and is thus the driest such period since precipitation records began in the fall of 1849. The previous driest Jan-March period was in 1851 when 3.20” was measured. The next (now 3rd) driest was during the great drought of 1975-1977 when only 3.31” was recorded in Jan-March 1976. It is quite astonishing to see the huge margin between this year’s driest ever Jan-March (2.30”) and the previous such record of 3.20” in 1851: a full 30%, and this for a site with 163 years of record.

Across the Bay from San Francisco, Oakland was even drier (it missed, for instance, the isolated rain cell that dropped heavy rain (.48”) on San Francisco yesterday. The January-March total for Oakland has been a meager 1.30” (JAN: .29”, FEB: .52”, MAR: .49”). The monthly totals in San Francisco were JAN: .49”, FEB: .85”, MAR: .96”. Oakland’s normal Jan-March rainfall is 12.60” so this year is running just 10% of normal at this time.

Here are some of the three-month totals (January-March 2013) for other sites in the San Francisco Bay Area and northern California (listed from north to south):

Eureka: 7.42” (normal 17.43”) 43% of normal

Redding: 4.96” (normal 15.84”) 31%

Santa Rosa: 3.74” (normal 18.43”) 20%

Sacramento: 2.70” (normal 10.78”) 25%

San Francisco (downtown): 2.30” (normal 12.22”) 19%

Oakland: 1.30” (normal 12.60”) 10%

San Jose: 1.68” (normal 8.72”) 19%

Fresno: 2.12” (normal 6.34”) 33%


April California Snow Survey Looking Grim

The latest Sierra snow survey by the California Department of Water Resources indicates that the water content of the snowpack in the Sierra Nevada is running at just 52% of normal for this time of year. This is down from 66% of normal at the time of the last survey March 1st. What is worse is that the snowpack is now melting, so there is little hope that the situation will improve, barring an exceptionally cold and wet April. What was looking like a promising year water-wise at the beginning of the year has now deteriorated drastically. These snowpack graphs for the three Sierra regions (southern, central, and northern sections) tell the story:







The blue lines indicate the wettest year on record (1982-1983), the brown lines the driest (1976-1977), the black lines normal, the green lines last year (2011-2012) and the pink lines this year (as of March 28th). The Sierra snowpack provides about one-third of all the water used in households and farms across the state. Graphs from the California Department of Water Resources.

Situation Not as Bad as it Sounds

Fortunately, there is still some time to make up for the current precipitation deficits. Some of California’s wettest storms on record have occurred in April. Furthermore, excessive rain and snowfall in late November and December have precluded any chance that this wet season will rank as among one of the driest despite the record dry spell. Because of the early season rains the state reservoirs are still close to capacity. It would take another dry season in 2013-2014 before serious drought conditions develop, at least for the northern two-thirds of the state.

Christopher C. Burt
Weather Historian