It Was a Historically Wet February in L.A., and Winter’s Not Over Yet

February was the wettest month in downtown Los Angeles since 1998. With over 12 inches of rain drenching the city, it was the fourth-wettest February — and the seventh-wettest month overall — in the city’s nearly 150-year recorded history.

You can feel the saturation in the soil, Park Williams, a professor and expert in water and drought, said in a phone interview last week as he was walking across the grass at the University of California, Los Angeles.

An astonishing 11 inches of rain fell in just two days in early February across the U.C.L.A. campus, which is tucked closer to the base of the Santa Monica Mountains than the downtown area. According to Dr. Williams’s calculations, that meant 1.1 billion pounds of water fell over the campus those two days.

The downtown area, a little farther east, received seven inches during that same period of time. A normal amount for the entire month of February is just under five inches for U.C.L.A. and four in downtown.

This large amount of rain, which fell during an atmospheric river event between Feb. 4 and Feb. 6, turned the typically low-flowing cement channels that meander through Los Angeles County into raging rivers nearly filled to the brim, causing hillsides in residential neighborhoods to give way and flooding streets. That event was followed by even more rain through the month, keeping the ground saturated and increasing the overall total.

Here’s a look at what the rain meant for the region.

The rain could help ease the megadrought.

Los Angeles was hit with a dangerous amount of historic rainfall, but the rain falling across California for the past month has also been beneficial. As of Tuesday, California had received slightly more rain than usual this winter — 103 percent of the average, according to state data.

That’s less than last year, when 141 percent of the normal amount fell and helped end drought conditions in the state. Other parts of the West have also seen improvement in the drought, and as of Tuesday, the U.S. drought monitor was reporting that only 27 percent of the region was in drought, a dramatic improvement from 2022, when 88 percent of the region was in drought.

“This could very well be the beginning of the end of the megadrought,” Dr. Williams said. “It’s been so wet these last couple of years that maybe we are, maybe we’re, on the path to do away with this drought.”

A megadrought is an extreme drought that lasts for many years; they are typically longer and more severe than short-term droughts that are more easily handled, Dr. Williams said. The current megadrought has been ongoing since 2000, and although it includes wet periods, the overall time period has been dryer than average.

… or it might not.

Dr. Williams had thought he might be seeing the end of the megadrought once before, during a really wet period between 2018 and 2019. Instead, in 2020, the West entered a period of three years that were about as dry as any of the others of the megadrought.

One or two really wet years sometimes aren’t enough to pull a region like the West out of a megadrought. Dr. Williams said that it could be years before we know if the last two were the beginning of the end of the megadrought.

If the next three years are extremely hot and dry, then the megadrought will continue. But if three out of the next five years are substantially wetter than average, then it is very likely that scientists will be able to say it’s over. “I do think that it will end sometime in the next decade,” Dr. Williams said.

Climate change is increasing the air temperature generally, and it can increase the amount of moisture the air can hold, which leads to more rainfall. Climate models suggest that the West will not only experience more severe droughts, but also have more intense rainfall events. This makes Dr. Williams nervous, he said, as his data shows that the intensity of rainfall in the West has yet to be significantly affected by climate change, yet rivers are already rising to the brim during intense rain events.

What to expect from March: more rain and a risk of landslides.

Despite the historic rainfall in February, the overall effects of the rain haven’t been as bad they could have been.

Joe Sirad, who has been a meteorologist with the National Weather Service in Los Angeles since 1996, said the winters of 1997-98 and 2004-2005 were tremendous for the amount of rainfall they delivered. While February of those years might not have reached the levels of this year, the months of December and January leading up to them were significantly wetter than this winter’s.

Overall, more than 17 inches of rain fell from Dec. 1 through the end of February. That was enough rain to make it the 13th wettest winter on record in downtown Los Angeles, and most of that rain fell in February. (The winter of 2004-5 holds the record for the most rain, with over 29 inches.)

Before February, the precipitation total in Los Angeles County was actually below average. It’s likely that because the soil wasn’t soaked from previous rains, the usual effects of intense rain, such as flash flooding and landslides, haven’t been as bad.

Forecasters at the Climate Prediction Center are confident that California will see above-average precipitation over the next couple of weeks.

Periods of intense rainfall typically trigger shallow landslides, but deeper landslides that are greater than three meters in depth have been known to develop during and well after rainstorms, said Matthew A. Thomas, a research hydrologist with the U.S. Geological Survey’s landslide hazards program.

“We should remain vigilant as we head into March,” Dr. Thomas said. “Southern California has experienced significant landslide activity during this time of year.”

Historically, March has also been very wet in Los Angeles — it was last year, Mr. Sirad said. The current weather pattern will also allow more stormy weather to bring additional rainfall to Los Angeles County this month.

While more water is good for the drought, Dr. Williams said, there’s a widespread opinion among experts that the area is probably about at the upper limit where more water is good.