A monsoon summer in the Southwest

How residents across the region are engaging with the yearly weather phenomenon.

When I moved to Tucson from western Colorado in the fall of 2019, I knew the weather would be warmer than I was used to. But the summer that followed turned out to be the hottest on record. I waited for the promised monsoon to cool things down, but that relief never came. Instead, I sweltered in my swamp-cooled duplex. 

Then, in mid-June this year, the monsoon season finally began. When the first rains hit, my partner, a Tucson resident for more than a decade, ran out into the street in our neighborhood to frolic in the torrent. As he pranced under dim streetlights, I worried that this storm would be like last year’s — the only rain of the season. What if it was the last monsoon ever? Given our increasingly unpredictable world, I decided to embrace the moment. I ran out, letting the rain soak through my clothes as a rush of water stormed down the street, my feet and ankles submerged in a dirty deluge. 


By July, the rain was making regular appearances. It was around that time that I first read about the Southwest Monsoon Fantasy Forecasts, an online game where people cast their monsoon predictions. That month turned out to be the wettest on record. It rained 8 inches in Tucson — the largest amount since the city started keeping track in the 1890s — a tremendous amount compared to the previous year’s 1.62 inches, and even to the yearly average, which is around 6 inches. Intrigued by how erratic the seasons seemed to be — and delighted by the prospect of winning a $400 backyard weather station that could track everything from wind speed to solar radiation — I decided to give the fantasy forecast a try. 

I created a username, joining the ranks of other amateur forecasters with imaginative monikers like “mesquite nerd” and “weather geek.” It was easy to log my guess for the month of August. Each city has its own page, with a bar graph depicting the median and mean rain totals, giving a sense of the usual rainfall. I moved a thick yellow line across the graph, contemplating my best estimates for El Paso, Flagstaff, Tucson, Phoenix and Albuquerque. Should I move the line closer to the right, showing how much I hoped for more rain? Or settle for a more conservative estimate? I imagined other weather enthusiasts across the West doing the same, attempting to make sense of a seasonal weather pattern that doesn’t seem to make sense much. I fiddled with my calculations for August and eventually settled on 1.8 inches, the median guess for Tucson. I didn’t believe our monsoon luck would continue past July.

What was brown and dry was now lush and green, and weeds flourished in the sidewalk cracks in the middle of August.

But August surpassed expectations again, with nearly 4 inches of rain. I was off, badly off, with my conservative estimate. It was worth it, though: The Tucson Mountains suddenly looked like a scene from Jurassic Park, with rocky slopes giving way to verdant valleys. What was brown and dry was now lush and green, and weeds flourished in the sidewalk cracks in the middle of August. Mesquite trees begin taking over my patio, and the mosquitos, which multiplied with the rain, eagerly dined out on my arms. But the rain brought problems of its own: While this year’s outsized monsoon storms were welcome, they were often accompanied by dangerous flooding that overwhelmed the desert arroyos and washes. Flash-flood notices lit up our phones all summer long in what an announcer at a local indie-movie theater called “a symphony of storm alerts.” 

Tucson, Arizona. August 17, 2021.

OVER THE PAST DECADE, the University of Arizona’s Climate Assessment for the Southwest program (CLIMAS) has hosted an entertaining podcast about local weather systems. And in recent years, there’s inevitably an episode where the usual hosts, Michael Crimmins and Zack Guido, researchers and professors at the University of Arizona, have a back-and-forth about their monsoon predictions. It was that dialogue that inspired them, along with fellow researcher and producer Ben McMahan, to create the monsoon game. “(We wanted) to find new ways of talking about the monsoon that engaged the public, because we know how it’s the single season that captivates the attention of people,” said Guido. 

For Crimmins, it was also an excuse to indulge his obsession with the monsoon rains. He says his moods are dictated by the season; during last summer’s “nonsoon,” he cycled through all five stages of grief. “It’s kind of like an emotional thing in that I go up and down with the dewpoint temperature,” he told me. He spends his days alternating between checking his fancy home weather station — which is similar to the prize that was being offered — and, when he’s out, scanning his phone to see if any storms are developing. “I even got it to show up on my smartwatch,” he said incredulously. “That’s not normal.” 

The game’s main purpose is to educate residents about our regional weather systems. “It’s not so much that we think people have some innate ability to know what the weather is going to be,” Guido explained. “But we do think the act of thinking about weather and climate is a very useful exercise for a whole bunch of reasons.” Monsoon game players are more likely to take their curiosity a step further, researching the region’s historical precipitation patterns and trying to deepen their understanding by comparing their own weather hunches to the scientific data. 

The monsoons are something that affect us all, whether we realize it or not, because they influence the regional temperatures — and, for those of us with swamp coolers, they either intensify or reduce our personal experience of humidity and heat. “It’s kind of like soccer or fútbol for Latin Americans,” Guido said. “It’s the thing that everybody can talk about, and that everyone loves to talk about and you can kind of find common ground.”

Tucson, Arizona. August 28, 2021.

The Southwest’s monsoon is driven by a complex host of factors. But at its most basic level, it forms when the land warms up at a different rate than the Pacific Ocean does, causing the wind direction to shift and allowing moisture to travel north from Mexico. Most of the monsoon rains are actually concentrated in Mexico. In the Southwest, we’re on the periphery of the weather pattern. But that still covers a lot of territory: The monsoon season extends all the way up to Colorado and Utah and influences weather across the entire West. Various factors, including the air pressure system known as the Four Corners High and the amount of moisture in the air, aligned this year to give us a “good” monsoon. “Wherever that high-pressure system is, is really, really important,” Crimmins said. “If it is above Arizona and New Mexico, then that moisture is pushed back into Mexico.” This year, it was positioned just right.

That’s why, Guido said, it’s harder than people think to connect extreme seasons — like this year’s remarkably good monsoon, say, or last season’s terribly dry one — to climate change. The dramatic differences between the two seasons represent an anomaly; it’s more likely that future changes from year to year will tend to be much subtler. “There’s so much variability that we would need long records, and highly dense records, to be able to find the trends in them. And we just don't have that,” he said. “We know that we've altered the amount of energy within our system, and we know that has an effect on the climate system because the climate system is about moving energy around,” he said. There’s a reason the 2021 report of the Intergovernmental Panel on Climate Change avoids making definitive statements about the future of the Southwest’s monsoon. “It’s a $10 million question,” Guido said.

“(We wanted) to find new ways of talking about the monsoon that engaged the public, because we know how it’s the single season that captivates the attention of people.”

 Throughout the rainy months of summer, for McMahan, the game provoked a kind of internal conflict between his desire to win the competition and the region’s desperate need for precipitation. “I want it to rain a certain amount, but then I kind of want it to stop raining, but I actually don't want it to stop raining,” he said when we spoke in August. “That cursing kind of talk is not acceptable about the monsoon.”

As of press time, my own guesses have me ranked at 144th place. By mid-September, Tucson’s monsoon season was already the third wettest on record. More than 12 inches of rain has fallen since June. Who could have predicted that?

Jessica Kutz is an assistant editor for High Country News. We welcome reader letters. Email her at [email protected] or submit a letter to the editor. See our letters to the editor policy.