People who don’t know any better like to say Los Angeles has no seasons, but that isn’t true; it has five overlapping seasons: the winter rainy season, spring, gloomy early summer (also known as jacaranda season), miserably hot late summer, which lasts through October, and Santa Ana season. For non-Angelenos, the most LA season is that brief spring, when the days are 72 degrees and sunny. But for Angelenos, who have a far more intimate relationship with both nature and apocalypse than the 72-degrees-and-sunny crowd will ever allow, the most Los Angeles season is Santa Ana season.

The mythology around the Santa Ana winds is potent enough that “Santa Ana winds in popular culture” has its own robust Wikipedia page, and they appear everywhere from Steely Dan’s “Babylon Sisters” to Bret Easton Ellis’s Less Than Zero to a season four episode of Beverly Hills, 90210. But the most-known and most-cited appearances are in the opening to Raymond Chandler’s story “Red Wind”:

There was a desert wind blowing that night. It was one of those hot dry Santa Anas that come down through the mountain passes and curl your hair and make your nerves jump and your skin itch. On nights like that every booze party ends in a fight. Meek little wives feel the edge of the carving knife and study their husbands’ necks. Anything can happen. You can even get a full glass of beer at a cocktail lounge.

and the first part of Joan Didion’s essay “Los Angeles Notebook”:

There is something uneasy in the Los Angeles air this afternoon, some unnatural stillness, some tension. What it means is that tonight a Santa Ana will begin to blow, a hot wind from the northeast whining down through the Cajon and San Gorgonio Passes, blowing up sandstorms out along Route 66, drying the hills and the nerves to flash point. For a few days now we will see smoke back in the canyons, and hear sirens in the night. I have neither heard nor read that a Santa Ana is due, but I know it, and almost everyone I have seen today knows it too. We know it because we feel it. The baby frets. The maid sulks. I rekindle a waning argument with the telephone company, then cut my losses and lie down, given over to whatever it is in the air. To live with the Santa Ana is to accept, consciously or unconsciously, a deeply mechanistic view of human behavior.

In a New York Times article in 1963, Eugene Burdick (who’d grown up in LA!) wondered for several pages how on earth California had recently passed New York to become the most populous state in the country. In 2016, his scene setting reads like a parody:

One summer day when a "Santa Ana" wind swept tons of desert dust aloft to combine with the smog to give Los Angeles a brown, hazy atmosphere, I visited Muscle Beach at Santa Monica. Sitting on a bench, peering through the warm, brown swirling air, were a dozen senior citizens watching a group of young men and women go through the tortures which produce heavily muscled and almost ridiculously perfect physiques.

Like every other common thing in Los Angeles, like everything else around here that Didion has turned her heavy-lidded eyes to, the winds have become a part of the story we tell ourselves about being Angelenos, like earthquakes and irritating development executives at parties, a mysterious force exotic enough to the folks Back East that they can use it to dismiss us.

Pleasant summer winds form over the Pacific Ocean. Santa Anas start in the Great Basin, beyond the Sierra Nevadas, in winter, when the air is cold and the jet stream leaves behind high-pressure systems, which spin clockwise, cold and dense, until the heavy air starts to slide down the mountains toward the coast. Lower pressure at the coast helps by sucking that cold air through the mountains toward Southern California. As it cascades down toward the Los Angeles basin, the air heats up and dries out, and it speeds up as it snakes its way through narrow passes and canyons, barreling out, finally, in the flats, blowing 110 miles per hour and 110 degrees, some days.

Santa Ana season lasts from October to April, but the winds blow just as hard (and sometimes harder) in September and May. Since the air in the Great Basin starts out hotter in those months, the Santa Anas blow hotter in Los Angeles, and they have a lot to do with those miserably hot late summers. “Typically the hottest daytime temperatures along the coast of Southern California have been recorded during Santa Ana winds,” Alexander Gershunov, a research meteorologist at the Scripps Institution of Oceanography, says.

Gershunov coauthored a paper published last month in Geophysical Research Letters about what he calls "the longest and probably most detailed record of Santa Ana winds available"—from 1948 to 2012. (The lead author was Janin Guzman-Morales, also of Scripps.)

The record reveals patterns in the wind’s behavior. They follow “a well-defined diurnal cycle,” says the paper, where they're strongest in the morning “and decay to their minimum in the late afternoon.” They’re more common in El Niño years, when storms off California drop the pressure way low on the coast. They blow most often in December, which is predictable, “because that’s when you have the coldest air masses, the longest nights in the High Desert… The longest nights and the weakest solar radiation.” But some of the strongest winds have blown in the early fall.

That’s bad news. In early fall, hillside plants have had all summer to dry out; the Santa Anas suck out any last moisture, and then all it takes is a poorly stamped out cigarette butt and the hills are on fire, flames fanned by more Santa Anas. Santa Ana fires burn harder, hotter, bigger, faster, and more often than other LA fires, and they burn closer to the city.

Or maybe Los Angeles is lucky and there is no fire on this particular Santa Ana day, but trees are uprooted, power’s lost, you wake up to a sickly yellow-pink sky and the dog skidding in frantic circles on the hardwood and the escalating feeling you've forgotten something annoying but important.

Can we blame the winds? Raymond Chandler isn’t the only one who holds the Santa Anas responsible for bad behavior—they’re said to cause migraines, irritability, even suicides and murders.

In the 19th century, the winds were thought to be cleansing—an 1886 report from the California State Board of Health called them "health-giving" and informed Californians that, after a bout of Santa Ana, "the atmosphere becomes wonderfully clear, pure, and invigorating."

That report also noted an improbable sounding electricity in the Santa Ana air:

During the progress of this wind the air is highly electrified. Horses’ tails stand out like thick brushes, the hair of the head crackles sharply when rubbed with the hand, and metallic bodies resting on an insulating material, such as dry wood, discharge themselves with visible sparks when a conductor is brought near. In one instance, it is said, the telegraph line between Los Angeles and Tucson, some four hundred and fifty miles in length, was detached from the battery and operated by the earth currents alone.

A man who wrote to the LA Times in 1893 to complain about the name of the Santa Anas still had to acknowledge that "it is generally admitted that the winds are beneficial to health, purifying the atmosphere and destroying germs of disease."

But nothing that powerful could possibly be good. By the 1960s, the Santa Anas had developed a reputation bad enough to attract a small amount of academic interest—in 1968, a geologist named Willis Miller published his findings that on about two-thirds of Santa Ana days, the homicide count in LA was above average. It’s not terribly convincing data, and since then only journalists seem to have looked into the connection. In 2008, Los Angeles magazine tallied up a 22 percent increase in domestic abuse reports made to the LAPD during a string of Santa Ana days, and a 30 percent increase in reports to the Santa Ana PD.

I have neither heard nor read that a Santa Ana is due, but I know it, and almost everyone I have seen today knows it too. We know it because we feel it.

- Joan Didion

Didion wrote that the wind’s effects force us to accept a mechanistic view of human behavior. So then what is the mechanism?

The Santa Anas are more or less a type of foehn, an ill wind that blows hot and dry down a mountainside, like the chinook in the far northwest of North America, the khamsin in North Africa, the zonda in the Andes. These hot winds might just be able to blow an electron off an air molecule, creating a precarious but possibly mischievous positive ion.

In the 1950s, a bacteriologist named Albert Krueger found that positive ions in the air could drive up the serotonin levels in a mouse’s blood and drive it down in the mouse’s brain. Serotonin can influence mood, migraines, breathing, and nausea. In 1974, a pharmacologist named Felix Sulman found high serotonin levels in the urine of Israelis who were sensitive to the sharav winds, and prescribed a strong dose of negative ions as the cure.

In 1981, social psychologists Jonathan Charry and Frank BW Hawkinshire published research suggesting that

mood changes…were present for most [subjects] when exposed to positive ions, [but] assessment of individual differences in susceptibility was essential for detecting effects on performance and physiological activation. For most [subjects], mood changes induced by ion exposure were characterized by increased tension and irritability.

They also found that when "ion-sensitive" subjects were exposed to positive ions, their skin became less conductive (this is a common psychological gauge) and their reaction times increased.

And in 2000, a group of neurologists published a study that found some migraineurs were more likely to get migraines on days before the chinook blew or on especially windy chinook days. But only two of their subjects got migraines on both types of days, and most got none at all.

So if you’ve gotten high off ions, get ready for the comedown: a 2013 meta-analysis of ion/mood studies carried out between 1957 and 2012 found “no consistent influence of positive or negative air ionization on anxiety, mood, relaxation, sleep, and personal comfort measures.” (It did conclude that negative ions might be able to reduce depression.)

The meek little wife Chandler evokes is a convenient lie. She’s just a psychopath or has snorted too much cocaine. That anxious feeling is really a hangover we don’t want to admit to ourselves and who ever knows why the dog does what she does. The science doesn't make a difference; Chandler and Didion and the rest of us just notice late in the afternoon when the air is staticky dry and hot that all day we’ve been getting the sense that something just beyond our reach has gone sour. It’s not the ions. It’s just the wind.

No one is too eager to tell the truth about the Santa Anas, least of all the Santa Anans of Orange County, whose city is miles away from the Santa Ana Canyon the winds are named for.

Santa Ana fires have burned pretty regularly from at least as far back as 1425, but no one seems to have asked or documented what the Tongva or Chumash called the winds. The earliest Anglos didn’t have a name—in a 1943 article in California Folklore Quarterly, Terry Stephenson cites Dana Point namesake Richard Henry Dana’s recollection of “a violent northeaster” in 1836.

Like a very boring noir, the Chamber of Commerce seems to be behind so many wrong things we all say about the Santa Ana winds.

By the end of that century, though, they were the Santa Ana winds. That 1886 California State Board of Health report says the Santa Ana got its name "because it frequently issues from the Santa Ana pass." An angry Santa Anan wrote to the LA Times in 1893 that the winds "take the name of Santa Ana by reason of their passage through the Santa Ana mountain cañon" (which was a "gross injustice to Santa Ana and Orange county"). In 1912, the LA Times said that "Early settlers in this part of Southern California gave the wind its name, because it was alleged to gain access to the region through the Santa Ana Canyon." The 1930s WPA guide for the region says the canyon "gave its name to the hot dry Santa Ana winds that occasionally sweep the southern California coastal counties."

Once he has made clear that "old-timers…have always known that the wind got its name because it swept out of the mouth of the Santa Ana canyon," Stephenson documents all the lies about how the winds got their name—a general named Santa Anna was known for his dust-kicking cavalry, there was a notable wind on St. Ann’s day (in July!) during the Spanish era, and the one that has stuck:

The idea was that everybody was mistaken about the name of the wind. It should be called a Santana, which, the Chamber of Commerce was told, was an Indian name for a desert wind...Nobody has ever named the tribe that was supposed to have used the name, and nobody has any story as to how away back yonder in the ’70’s settlers in the Santa Ana Valley managed ingloriously to twist the name into Santa Ana.

By 1967, this story had twisted into this story, in the LA Times:

Others said the Spanish padres translated the Indian term for devil wind into "viente satanas" (wind of Satan). Satanas and Santana had been corrupted into Santa Ana, they said. Santana was and still is widely believed to be the true name of the winds which originated with the Indians. However, a recognized authority on Indian language says no such word as Santana ever existed.

Like a very boring noir, the Chamber of Commerce seems to be behind so many wrong things we all say about the Santa Ana winds. In 1912, the LA Times reported that they had

fathered a movement and campaign of education to get rid of the name Santa Ana as attached to the desert wind that pays occasional visits to parts of Southern California. The directors have passed a resolution asking the newspapers to call the wind a norther or a desert wind, anything so long as it be no longer designated as a Santa Ana wind. The public is called upon to refrain from referring to the wind in letters and conversation as a Santa Ana wind.

Some Orange County businessmen threw a tantrum and now here we are a century later saying "Devil Winds." On the other hand, as Stephenson writes, "at Santa Ana and everywhere else the wind was still a Santa Ana."

We don’t seem to have changed the winds, but we have accidentally helped to make them more dangerous.

Global warming is expected to heat the Great Basin faster than the coast, which should mean less cold air and high pressure to fuel the Santa Anas, but so far that hasn’t happened. “There already has been a warming—not as much as we expect in the future—but we don’t see any reduction of Santa Ana winds activity in the long record of Santa Ana winds,” says Gershunov. He says that the strength with which the winds blow in warmer months like September “tells me the intensity of Santa Ana winds is not controlled just by the temperature of the cold air mass over the Great Basin…In the global warming context, it seems that the answer is more complicated.”

Actually, Gershunov and his coauthors “didn’t really see any significant changes in wind frequency or anything else” over 65 years of Santa Anas. Except for one thing: “extreme Santa Ana winds seem to be getting more common, at the expense of run-of-the-mill events,” but they don’t think that has anything to do with global warming; it seems to correspond instead to the Great Pacific Climate Shift of the 1970s (which is pretty much what it sounds like, but we’ll talk about it another time).

“We don’t really understand right now how the Santa Ana winds might change in a warming climate,” but scientists have a much better idea of how precipitation will change: there's probably going to be a lot less of it in Southern California. Southern California fire season comes in the fall, later than the rest of the western United States, because of the Santa Anas. But parched vegetation is the fuel, and the longer the dry season lasts into winter, the longer vegetation stays parched, the longer Santa Ana season has to set it all on fire.

We’ll leave our mark before we’re done here in the basin, but the Santa Anas were blowing long before Los Angeles began and they’ll be blowing long after it’s gone. The city they dishevel today isn’t the same one Chandler and Didion wrote the myths of so many decades ago—here at the beginning of the 21st century, we have different priorities and we’re writing new myths. But while we might demolish the freeways and the stripmalls, or build towers on every block, the mountains will always rise up in a ring around Los Angeles; the cold, high air will always be pulled down through the canyons, taking on heat, whipping up any palm leaves that are left, unsettling the locals, whatever beasts they may be.



