The Weather Man

Daniel Swain studies extreme floods. And droughts. And wildfires. Then he explains them to the rest of us.

March 2024

Reading time min

An illustration of Daniel Swain walking through the mountains and clouds.

Illustrations by Tim O'Brien

7:00 a.m., 45 degrees F

The moment Daniel Swain wakes up, he gets whipped about by hurricane-force winds. “A Category 5, literally overnight, hits Acapulco,” says the 34-year-old climate scientist and self-described weather geek, who gets battered daily by the onslaught of catastrophic weather headlines: wildfires, megafloods, haboobs (an intense dust storm), atmospheric rivers, bomb cyclones. Everyone’s asking: Did climate change cause these disasters? And, more and more, they want Swain to answer.

Swain, PhD ’16, rolls over in bed in Boulder, Colo., and checks his cell phone for emails. Then, retainer still in his mouth, he calls back the first reporter of the day. It’s October 25, and Isabella Kwai at the New York Times wants to know whether climate change is responsible for the record-breaking speed and ferocity of Hurricane Otis, which rapidly intensified and made landfall in Acapulco as the eastern Pacific’s strongest hurricane on record. It caught everyone off guard. Swain posted on X (formerly known as Twitter) just hours before the storm hit: “A tropical cyclone undergoing explosive intensification unexpectedly on final approach to a major urban area . . . is up there on list of nightmare weather scenarios becoming more likely in a warming #climate.”

Swain is simultaneously 1,600 miles away from the tempest and at the eye of the storm. His ability to explain science to the masses—think the Carl Sagan of weather—has made him one of the media’s go-to climate experts. He’s a staff research scientist at UCLA’s Institute of the Environment and Sustainability who spends more than 1,100 hours each year on public-facing climate and weather communication, explaining whether (often, yes) and how climate change is raising the number and exacer­bating the viciousness of weather disasters. “I’m a physical scientist, but I not only study how the physics and thermo­dynamics of weather evolve but how they affect people,” says Swain. “I lead investigations into how extreme events like floods and droughts and wildfires are changing in a warming climate, and what we might do about it.”

He translates that science to everyday people, even as the number of weather-disaster headlines grows each year. “To be quite honest, it’s nerve-racking,” says Swain. “There’s such a demand. But there’s a climate emergency, and we need climate scientists to talk to the world about it.”

No bells, no whistles. No fancy clothes, makeup, or vitriolic speech. Sometimes he doesn’t even shave for the camera. Just a calm, matter-of-fact voice talking about science on the radio, online, on TV. In 2023, he gave nearly 300 media interviews—sometimes at midnight or in his car. The New York Times, CNN, and BBC keep him on speed dial. Social media is Swain’s home base. His Weather West blog reaches millions. His weekly Weather West “office hours” on YouTube are public and interactive, doubling as de facto press conferences. His tweets reach 40 million people per year. “I don’t think that he appreciates fully how influential he is of the public understanding of weather events, certainly in California but increasingly around the world,” says Stanford professor of earth system science Noah Diffenbaugh, ’96, MS ’97, Swain’s doctoral adviser and mentor. “He’s such a recognizable presence in newspapers and radio and television. Daniel’s the only climate scientist I know who’s been able to do that.”

Illustration of Daniel Swain's reflection in a puddle.

There’s no established job description for climate communicator—what Swain calls himself—and no traditional source of funding. He’s not particularly a high-energy person, nor is he naturally gregarious; in fact, he has a chronic medical condition that often saps his energy. But his work is needed, he says. “Climate change is an increasingly big part of what’s driving weather extremes today,” Swain says. “I connect the dots between the two. There’s a lot of misunderstanding about how a warming climate affects day-to-day variations in weather, but my goal is to push public perception toward what the science actually says.” So when reporters call him, he does his best to call them back. 


7:30 a.m., winds at 5 mph from the east northeast

Swain finishes the phone call with the Times reporter and schedules a Zoom interview with Reuters for noon. Then he brushes his teeth. He’s used to a barrage of requests when there’s a catastrophic weather event. Take August 2020, when, over three days, California experienced 14,000 lightning strikes from “dry” thunderstorms. More than 650 reported wildfires followed, eventually turning the skies over San Francisco a dystopian orange. “In a matter of weeks, I did more than 100 interviews with television, radio, and newspaper outlets, and walked a social media audience of millions through the disaster unfolding in their own backyards,” he wrote in a recent essay for Nature.

Swain’s desire to understand the physics of weather stretches back to his preschool years. In 1993, his family moved from San Francisco across the Golden Gate Bridge to San Rafael, and the 4-year-old found himself wondering where all that Bay City fog had gone. Two years later, Swain spent the first big storm of his life under his parents’ bed. He lay listening to screeching 100 mile-per-hour winds around his family’s home, perched on a ridge east of Mount Tamalpais. But he was more excited than scared. The huge winter storm of 1995 that blew northward from San Francisco and destroyed the historic Conservatory of Flowers just got 6-year-old Swain wired.

‘Climate change is an increasingly big part of what’s driving weather extremes today. I connect the dots between the two.’

“To this day, it’s the strongest winds I’ve ever experienced,” he says. “It sent a wind tunnel through our house.” It broke windows. Shards of glass embedded in one of his little brother’s stuffies, which was sitting in an empty bedroom. “I remember being fascinated,” he says. So naturally, when he got a little older, he put a weather station on top of that house. And then, in high school, he launched his Weather West blog. “It was read by about 10 people,” Swain says, laughing. “I was a weather geek. It didn’t exactly make me popular.” Two decades, 550 posts, and 2 million readers later, well, who’s popular now?

Swain graduated from UC Davis with a bachelor’s degree in atmospheric science. He knew then that something big was happening on the weather front, and he wanted to understand how climate change was influencing the daily forecast. So at Stanford, he studied earth system science and set about using physics to understand the causes of changing North Pacific climate extremes. “From the beginning, Daniel had a clear sense of wanting to show how climate change was affecting the weather conditions that matter for people,” says Diffenbaugh. “A lot of that is extreme weather.” Swain focused on the causes of persistent patterns in the atmosphere—long periods of drought or exceptionally rainy winters—and how climate change might be exacerbating them.

The first extreme weather event he studied was the record-setting California drought that began in 2012. He caught the attention of both the media and the scientific community after he coined the term Ridiculously Resilient Ridge, referring to a persistent ridge of high pressure caused by unusual oceanic warmth in the western tropical Pacific Ocean. That ridge was blocking weather fronts from bringing rain into California. The term was initially tongue-in-cheek. Today the Ridiculously Resilient Ridge (aka RRR or Triple R) has a Wikipedia page.

“One day, I was sitting in my car, waiting to pick up one of my kids, reading the news on my phone,” says Diffenbaugh. “And I saw this article in the Economist about the drought. It mentioned this Ridiculously Resilient Ridge. I thought, ‘Oh, wow, that’s interesting. That’s quite a branding success.’ I click on the page and there’s a picture of Daniel Swain.”

Diffenbaugh recommended that Swain write a scientific paper about the Ridiculously Resilient Ridge, and Swain did, in 2014. By then, the phrase was all over the internet. “Journalists started calling while I was still at Stanford,” says Swain. “I gave into it initially, and the demand just kept growing from there.”


11:45 a.m., precipitation 0 inches

Swain’s long, lanky frame is seated ramrod straight in front of his computer screen, scrolling for the latest updates about Hurricane Otis. At noon, he signs in to Zoom and starts answering questions again.

Reuters: “Hurricane Otis wasn’t in the forecast until about six to 10 hours before it occurred. What would you say were the factors that played into its fierce intensification?”

Swain: “Tropical cyclones, or hurricanes, require a few different ingredients. I think the most unusual one was the warmth of water temperature in the Pacific Ocean off the west coast of Mexico. It’s much higher than usual. This provided a lot of extra potential intensity to this storm. We expect to see increases in intensification of storms like this in a warming climate.”

Swain’s dog, Luna, bored by the topic, snores softly. She’s asleep just behind him, next to a bookshelf filled with weather disaster titles: The Terror by Dan Simmons; The Water Will Come by Jeff Goodell; Fire Weather by John Vaillant. And the deceptively hopeful-sounding Paradise by Lizzie Johnson, which tells the story of the 2018 Camp Fire that burned the town of Paradise, Calif., to the ground. Swain was interviewed by Johnson for the book. The day of the fire, he found himself glued to the comment section of his blog, warning anyone who asked about evacuation to get out.

“During the Camp Fire, people were commenting, ‘I’m afraid. What should we do? Do we stay or do we go?’ Literally life or death,” he says. He wrote them back: “There is a huge fire coming toward you very fast. Leave now.” As they fled, they sent him progressively more horrifying images of burning homes and trees like huge, flaming matchsticks. “This makes me extremely uncomfortable—that I was their best bet for help,” says Swain.

Swain doesn’t socialize much. He doesn’t have time. His world revolves around his home life, his work, and taking care of his health. He has posted online about his chronic health condition, Ehlers-Danlos syndrome, a heritable connective tissue disease that, for him, results in fatigue, gastrointestinal problems, and injuries—he can partially dislocate a wrist mopping the kitchen floor. He works to keep his health condition under control when he has down time, traveling to specialists in Utah, taking medications and supplements, and being cautious about any physical activity. When he hikes in the Colorado Rocky Mountains, he’s careful and tries to keep his wobbly ankles from giving out. Doctors don’t have a full understanding of EDS. So, Swain researches his illness himself, much like he does climate science, constantly looking for and sifting through new data, analyzing it, and sometimes sharing what he discovers online with the public. “If it’s this difficult to parse even as a professional scientist and science communicator, I can only imagine how challenging this task is for most other folks struggling with complex/chronic illnesses,” he wrote on Twitter. 

‘“There is a huge fire coming toward you very fast. Leave now.” This makes me extremely uncomfortable—that I was their best bet for help. ’

It helps if he can exert some control over his own schedule to minimize fatigue. The virtual world has helped him do that. He mostly works from a small, extra bedroom in an aging rental home perched at an elevation of 5,400 feet in Boulder, where he lives with his partner, Jilmarie Stephens, a research scientist at the University of Colorado Boulder.

When Swain was hired at UCLA in 2018, Peter Kareiva, the then director of the Institute of the Environment and Sustainability, supported a nontraditional career path that would allow Swain to split his time between research and climate communication, with the proviso that he find grants to fund much of his work. That same year, Swain was invited to join a group at the National Center for Atmospheric Research (NCAR) located in Boulder, which has two labs located at the base of the Rocky Mountains. 

“Daniel had a very clear vision about how he wanted to contribute to science and the world, using social media and his website,” says Kareiva, a research professor at UCLA. “We will not solve climate change without a movement, and communication and social media are key to that. Most science papers are never even read. What we do as scientists only matters if it has an impact on the world. We need at least 100 more Daniels.”

And yet financial support for this type of work is never assured. In a recent essay in Nature, Swain writes about what he says is a desperate need for more institutions to fund climate communication by scientists. “Having a foot firmly planted in both research and public-engagement worlds has been crucial,” he writes. “Even as I write this, it’s unclear whether there will be funding to extend my present role beyond the next six months.”


4:00 p.m., 67 degrees F

“Ready?” says the NBC reporter on the computer screen. “Can we just have you count to 10, please?”

“Yep. One, two, three, four, five, six, seven, eight, nine, 10,” Swain says.

“Walk me through in a really concise way why we saw this tropical storm, literally overnight, turn into a Category 5 hurricane, when it comes to climate change,” the reporter says.

“So, as the Earth warms, not only does the atmosphere warm or air temperatures increase, but the oceans are warming as well. And because warm tropical oceans are hurricane fuel, the maximum potential intensity of hurricanes is set by how warm the oceans are,” Swain says.

An hour later, Swain lets Luna out and prepares for the second half of his day: He’ll spend the next five hours on a paper for a science journal. It’s a review of research on weather whiplash in California—the phenomenon of rapid swings between extremes, such as the 2023 floods that came on the heels of a severe drought. Using atmospheric modeling, Swain predicted in a 2018 Nature Climate Change study that there would be a 25 percent to 100 percent increase in extreme dry-to-wet precipitation events in the years ahead. Recent weather events support that hypothesis, and Swain’s follow-up research analyzes the ways those events are seriously stressing California’s water storage and flood control infrastructure.

“What’s remarkable about this summer is that the record-shattering heat has occurred not only over land but also in the oceans,” Swain explained in an interview with Katie Couric on YouTube in August, “like the hot tub [temperature] water in certain parts of the shallow coastal regions off the Gulf of Mexico.” In a warming climate, the atmosphere acts as a kitchen sponge, he explains later. It soaks up water but also wrings it out. The more rapid the evaporation, the more intense the 
precipitation. When it rains, there are heavier downpours and more extreme flood events.

‘What we do as scientists only matters if it has an impact on the world. We need at least 100 more Daniels.’

“It really comes down to thermo­dynamics,” he says. The increasing temperatures caused by greenhouse gases lead to more droughts, but they also cause more intense precipitation. The atmosphere is thirstier, so it takes more water from the land and from plants. The sponge holds more water vapor. That’s why California is experiencing these wild alternations, he says, from extremely dry to extremely wet. “It explains the role climate change plays in turning a tropical storm overnight into hurricane forces,” he says.


October 26, expected high of 45 degrees F

In 2023, things got “ludicrously crazy” for both Swain and the world. It was the hottest year in recorded history. Summer temperatures broke records worldwide. The National Oceanic and Atmospheric Administration reported 28 confirmed weather/climate disaster events with losses exceeding $1 billion—among them a drought, four flooding events, 19 severe storm events, two tropical cyclones, and a killer wildfire. Overall, catastrophic weather events resulted in the deaths of 492 people in the United States. “Next year may well be worse than that,” Swain says. “It’s mind-blowing when you think about that.” 

“There have always been floods and wildfires, hurricanes and storms,” Swain continues. “It’s just that now, climate change plays a role in most weather disasters”—pumped-up storms, more intense and longer droughts and wildfire seasons, and heavier rains and flooding. It also plays a role in our ability to manage those disasters, Swain says. In a 2023 paper he published in Communications Earth & Environment, for example, he provides evidence that climate change is shifting the ideal timing of prescribed burns (which help mitigate wildfire risk) from spring and autumn to winter.

The day after Hurricane Otis strikes, Swain’s schedule has calmed down, so he takes time to make the short drive from his home up to the NCAR Mesa Lab, situated in a majestic spot where the Rocky Mountains meet the plains. Sometimes he’ll sit in his Hyundai in the parking lot, looking out his windshield at the movements of the clouds while doing media interviews on his cell phone. Today he scrolls through weather news updates on the aftermath of Hurricane Otis, keeping informed for the next interview that pops up, or his next blog post. In total, 52 people will be reported dead due to the disaster. The hurricane destroyed homes and hotels, high-rises and hospitals. Swain’s name will appear in at least a dozen stories on Hurricane Otis, including one by David Wallace-Wells, an opinion writer for the New York Times, columnist for the New York Times Magazine, and bestselling author of The Uninhabitable Earth: Life After Warming. “It’s easy to get pulled into overly dramatic ways of looking at where the world is going,” says Wallace-Wells, who routinely listens to Swain’s office hours and considers him a key source when he needs information on weather events. “Daniel helps people know how we can better calibrate those fears with the use of scientific rigor. He’s incredibly valuable.”

From the parking lot in the mountains, Swain often watches the weather that blows across the wide-open plains that stretch for hundreds of miles, all the way to the Mississippi River. He never tires of examining weather in real time, learning from it. He studies the interplay between the weather and the clouds at this spot where storms continually roll in and roll out.

“After all these years,” he says, “I’m still a weather geek.” 

Tracie White is a senior writer at Stanford. Email her at traciew@stanford.edu.

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