Rainy season runs dry in the Coachella Valley as winter and spring see low precipitation

Put away those umbrellas and get ready for the heat. While coastal California and local mountains saw another soaking rainstorm recently, the Coachella Valley stayed bone dry, and is likely to remain that way until possible summer monsoons blow through, experts say — or even into next year's rainy season.

Perhaps surprisingly, Palm Springs and neighboring cities also received below normal rainfall this winter and spring, with just 3.20 inches from Oct. 1 through May 5.

That's 0.77 inches, or almost 20%, less than the normal 3.97 inches for that span, said meteorologist Brandt Maxwell with the National Weather Service in San Diego.

The desert floor often gets left in the dust, so to speak, when moisture blowing from the coast isn't deep enough to clear mountain tops and rain down here, Maxwell explained. That's what happened last weekend, when 1.28 inches drenched Running Springs and other spots in the San Bernardino Mountains on Sunday, May 5. But the moisture was only about 8,000 feet high and winds were blowing straight from the west rather than the southwest. That meant clouds didn't make it above the crests, and instead fell over the mountain slopes and evaporated, rather than staying aloft at a mile or two and wetting the desert.

Temperatures were a bit cooler overall this winter, but don't get used to it. Remember that freakishly hot day a few weeks back, on April 22, when it hit 100 in the valley for the first time this year? Climate Central, a science and meteorology group based in Princeton, New Jersey, that uses a peer-reviewed modeling technique to detect "fingerprints of climate change," predicted in advance that temperatures that night were two times more likely to be warmer than historical averages, due to human-caused atmospheric global warming that is making weather events across the planet more frequent and more extreme.

For the California deserts, that means hotter temperatures are gradually occurring over time. But although the trends are clear, there is still daily variability. You can check the likely impacts of climate change on the day's weather in your area via Climate Central's Climate Shift Index .

In addition to global patterns, local "urban heat islands" also keep nighttime temperatures above normal, Maxwell with the National Weather Service said. Large concrete structures like new sports arenas, massive warehouses, lots of dark, heat-capturing asphalt around them, and more people in a single area all contribute, he said.

"More and more, as the Coachella Valley fills up with infrastructure, it's more likely to have really warm nights. The effect on the daytime temperatures isn't quite as much," he said.

Still, warmer nights can pose health risks, if people can't cool down as much. As for the gusty days, spring is normally when winds blow the hardest through the San Gorgonio Pass and across the valley. But, Maxwell said, the rain and the wind have often occurred on weekends the past few months, which people tend to notice more than during the work week.

He added, "The relatively mild weather we're having now here, it's not going to last much longer." Glancing at his tracking instruments on Monday, Maxwell said, I see it's only 87 degrees at the (Palm Springs) airport right now (the average temperature is 91 degrees for that day). I think a month from now, if it's only 87, people will be like, "Wow, what's wrong?'"

Janet Wilson is senior environment reporter for The Desert Sun and co-authors USA Today Climate Point. She can be reached at jwilson@gannett.com

This article originally appeared on Palm Springs Desert Sun: Rainy season runs dry in the Coachella Valley as winter and spring see low precipitation