Daily Archives: January 1, 2017

SoCal Rain: A New Hope?

Last year, El Niño brought lots of rain and snow to northern California, but SoCal residents watched storm after storm pass us by, leaving us with a fifth year of drought. The five-year period 2011-2016 was by far the driest on record, with 38.79” of rain compared to the previous record of 45.63” in the drought of the late 1980s, and an average of 73.70”. (Remember that in California we measure precipitation from October through the following September; this period is called the water year.)

There’s been some positive press lately about the rainstorms we’ve had so far this winter, with December 2016 the wettest month for downtown LA since December 2010. This is true, though this December (4.55”) wasn’t really in the same league as December 2010 (10.23”). December 2010 delivered more rain in one month than any of the drought years other than 2014-2015, which was juiced by tropical storm remnants in September 2015.

Looking at this year in context, we are off to a good start, with 5.95” so far. That already surpasses the worst year of the drought (2012-2013, 5.93”) and is less than an inch away from last year’s final total.


While last month was encouraging, every drought year has had at least one respectable month of rain. We need about 8.5” more this winter, which would give us an average year, just to save us from having the driest six-year period on record. To start making up lost precipitation from the drought, we need the storms to keep rolling through the next few months, so let’s hope they do!

Looking a little more broadly at SoCal, we can see that much of the region has fared better than LA.


(Note: ignore the below normal precipitation along the immediate coast and just offshore, which is a systematic error in the map.)

San Diego County, Orange County, and the Inland Empire are all a little bit more above normal than we are in LA. The SoCal mountain ranges have done even better; the five light blue areas east of LA are the San Gabriel, San Bernardino, San Jacinto, San Diego County, and Santa Ana Mountains (starting top left and going clockwise). This is really good news for the forests and wildlife in SoCal’s wild areas.

The unfortunate exception is parts of the Ventura County and Santa Barbara County mountains in the Los Padres National Forest. Since these areas depend on local water supplies more than other parts of SoCal, they really need to catch up. Let’s hope the storms keep coming and that everyone gets their share of the action!