Spring is just about here, if you go by its official start date, on the equinox. But in the American West, it feels like we skipped right to summer. A record-smashing heat dome has settled over a huge swath of the United States, from California to Montana and down to Texas. At my house in Colorado Springs, where we are 6,700 feet in elevation, highs could hit 90 degrees Fahrenheit this Saturday. The usual high temperature should be around 55 this time of year. Just outside Phoenix, a baseball spring-training matchup between the Chicago Cubs and Cincinnati Reds was rescheduled to 6:05 p.m. Friday, rather than a typical afternoon start time. Highs around Phoenix are expected to hit 106 Friday and Saturday, about 30 degrees above normal for mid-March. We are roasting out here.This is not normal. Or at least it wasn’t normal in the past. The heat wave is happening because of a bizarrely strong ridge of high pressure in Earth’s atmosphere. The ridge suppresses cloud formation and brings in warmer air. Such atmospheric ridges are more common in the summer, but this one would be unusually intense even for that season. It is the strongest ridge ever observed in March, Kaitlyn Trudeau, a senior researcher at the science nonprofit group Climate Central, told me. The group’s researchers have developed a prediction model that assesses how much a warming trend or record high can be attributed to human-caused climate change. According to the model, climate change is making this week’s western high temps five times more likely.More subjectively, this heat dome is “otherworldly,” “genuinely startling,” and “absurd,” depending on which meteorologist you ask. The spread of March temperatures on Colorado’s Front Range is typically wide, but not so wide that the Denver metro area should be expecting highs in the 80s—even inching up to 90. March is also, famously, the state’s snowiest month. Peak snowpack usually falls around April 9. This year, we passed peak snowpack a couple of weeks ago, and the heat wave means that by mid-April, much of the snow will probably be gone for the season.This is not just our problem, or Arizona’s; the whole West is baking right now. In Nevada, a state whose name literally means “snowy,” Great Basin National Park will see temperatures in the 70s. From March 4 to March 16 in California, the snowpack melted at 1 percent a day on average, according to the state’s Department of Water Resources. Peak snowpack in the state probably happened in mid-February, about 40 days before the typical peak.Snowpack is vital for water in the West, serving as a savings account for summer water needs; the heat wave will flush that account empty. My favorite Colorado ski area, which reaches 11,952 feet in elevation at its summit, could see high temperatures of 55 degrees over the weekend, for instance. The snow will turn to slush and melt fast, and streams will be high and turbid; one of the threats from this heat wave is actually hypothermia, for people who find themselves (intentionally or otherwise) in rushing, snow-fed rivers. But then the rivers and lakes filled by melting snow will run dry, months sooner than they should. Lake Powell and Lake Mead will drop, maybe by a lot. The parched ground throughout western states will become a tinderbox. Already, communities in the Denver metro area have declared Stage 1 drought, and others are considering the same, which means restrictions on water use. Governor Jared Polis activated the state drought task force on Tuesday, often a harbinger of statewide-drought declaration. Again, let me punctuate that this is happening in the middle of March.“This is exactly the opposite of what you want to see at this point,” Trudeau said.This oddly powerful heat wave caps off an already anomalous, ominous winter season. February closed out the warmest winter ever measured in Colorado. Together, December, January, and February were a whopping 8.1 degrees warmer than the 20th-century average, and 6.4 degrees warmer than the 1991–2020 average. It was by far the warmest winter here in all 131 years of recordkeeping. Many locations around the state shattered previous records for the number of winter days above 60 degrees.The falling records are a symptom of change, and could portend a new normal, Trudeau said.“It’s going to become increasingly harder to use the past as a playbook for the future, because we are shifting into a completely different climate system.” For those of us who grew up here and remember what it’s supposed to be like, this week’s weather feels wrong, especially after we didn’t really have a winter.At the same time, we have some experience with what that could mean for the other three seasons. I keep thinking back to 2012, when I was living in the Midwest, homesick for the mountains, and watching them burn on national TV. That year was also weirdly hot—it was the hottest year on record for the continental United States until 2024—and Colorado suffered immensely. Wildfires raged across every corner of the state, and Front Range communities burned from Colorado Springs to Fort Collins. That summer, black smoke billowed over Colorado Springs and officials evacuated the Air Force Academy. We worry about reliving the terrifying scene this year, from the mountains to the prairies.While I was working on this article, I got an alert from the Watch Duty app about a new grass fire 20 minutes south of my house. We are getting too accustomed to springtime fire watches and warnings. But besides grass fires here and there, as of this writing, nothing catastrophic has yet begun in the mountains. I think about how one brutal fire season, Colorado’s then-governor, Bill Owens, was infamously quoted saying that “all of Colorado is burning.” Right now all of Colorado is hot, and all of Colorado is dry. We are all bracing for what that means for us in a few months.