Los Altos Weather: 2015

December weather in Los Altos, California, was about average. But our 2015 rainfall was only 53% of normal. Local users continue to conserve water, and the groundwater level in our aquifer rose in 2015. Conditions look good for a wet winter. 🙂

Los Altos weather

Our December rainfall was about one inch below normal, and our cumulative rainfall for the past three years was 56% of normal.

December rainfall one inch below normal
December rainfall one inch below normal
Rainfall for past 3 years is 56% of normal
Rainfall for past 3 years is 56% of normal

December temperatures were close to normal, much better than the higher-than-normal temperatures we’ve had most of the past 3 years. Our monthly low temperatures have almost always been higher than normal, with only two months out of the past 36 months being less than the normal.

December temperatures normal
December temperatures normal

Water conservation continues and aquifer improves

Our residents continue to conserve water in the winter, when outdoor watering decreases. In November, we used 42% less water than two years ago, surpassing the 32% standard set by the state. Over the past six months, we conserved 38%.

Our conservation is paying off because the water level in our aquifer continues to rise despite the drought. In the groundwater elevation chart below, the level of groundwater under the Santa Clara Valley steadily rose throughout 2015, in contrast with every prior years since 2013, when the groundwater elevation dropped during the summer. Note that the recharge and pumping graphs have different vertical scales. During 2015 we pumped more than 40,000 acre-feet of water than we recharged through percolation ponds. And the groundwater increased.

Groundwater increases throughout 2015
Groundwater increases throughout 2015 (Santa Clara Valley Water District)

The groundwater in California’s largest aquifer continues to be overdrawn, but an irrigation district is preparing to recharge groundwater, just as our valley does. Recharging groundwater is faster and perhaps cheaper than building dams. The best sites for dams have been already used, and dams have limited lives since the reservoir fills with silt.

El Niño

The US Weather Service forecasts above-normal rainfall for California during the next three months, so there’s hope for the future!

Above-average rainfall for California
Above-average rainfall forecast for California (US NOAA)

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I enjoy travel, art, food, photography, nature, California native plants, history, and yoga. I am a retired software engineer. The gravatar is a Nuttall's woodpecker that visited our backyard.

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