Something feels off this week if you step outside in the Coachella Valley. The light still has that low, golden, late-winter slant. The wildflowers are still blooming. And yet the thermometer is reading temperatures that wouldn’t be out of place in late June.
This week, parts of the desert Southwest are expected to shatter records — not just for March, but for the earliest readings of their kind ever logged. For those of us who live in, write about, or love the desert Southwest, this moment is worth pausing on.
What’s Actually Happening
A prolonged stretch of extreme heat is gripping the western United States from Wednesday March 18 through Saturday, March 21. Temperatures are running 20°F to 30°F above normal across much of the region, with widespread highs reaching into the 90s and 100s.
For the Coachella Valley, the numbers are striking: forecasts call for temperatures ranging from 105°F to 108°F during the peak of the event. An Extreme Heat Warning is in effect for Riverside, Los Angeles, Orange, and San Bernardino counties from 10 a.m. Wednesday through 8 p.m. Saturday.
But it’s not just the heat — it’s the timing. According to the National Weather Service, many locations are likely to set both all-time high temperatures for the month of March and their earliest 100-degree reading on record.
March 12 already gave us a preview — Palm Springs hit 97°F that day, setting a new daily record. That was just the warmup.
It could be hotter than it has ever been anywhere in the US in the month of March ever – if Palm Springs tops 108F this Friday! (Source: Climate Central)
Let that sink in!!
This Isn’t Just Weather
Here’s what makes this week more than just a dramatic forecast: scientists can now measure climate change’s fingerprint on specific heat events.
Climate Central’s Climate Shift Index (CSI) does exactly that — it tells you how much more likely a given temperature has become because of human-caused climate change. Think of it as a multiplier. A score of 4 means this heat is at least four times more likely to occur today than it would have been before fossil fuels began warming the planet.
This week, Palm Springs scores a CSI Level 5 — that’s the top of the scale: a 5 out of 5! And this can be seen across Southern California, Arizona, Nevada, Utah, and parts of Colorado, New Mexico and Oregon — meaning their heat is at least five times more likely because of climate change. In total, more than 26 million people in the western U.S. will experience at least one of those Level 5 days this week.
The Snowpack Problem No One’s Talking About
The heat story doesn’t end at the desert’s edge. Across the West this winter, snowpack is already critically low — a widespread snow drought driven by warmer-than-normal temperatures. And the timing of this heat wave is particularly damaging.
April 1 is the traditional date of peak snowpack in the West — the moment when snow water storage is at its highest before spring melt begins. Water managers, farmers, and river system planners all use this date as a key benchmark. Sierra snowpack entered this week at roughly half its historical average — and that was before this week’s temperatures began accelerating melt. The Northern Sierra, which feeds California’s largest reservoirs, stood at just 46% of normal as of late February. By March 1, nearly 20% of the statewide snowpack had already melted — timing more typical of May. This week will push those numbers lower still.
For desert Southwest readers, the downstream consequences are real: less stored water, earlier and faster runoff, and a drier summer outlook for a region already navigating long-term water scarcity. Watch for updated snowpack figures on April 1, when Climate Central will publish their full seasonal analysis.
What This Means on the Ground Here
Spring in the desert runs on cues: rainfall totals, overnight temperatures, the gradual lengthening of days. When temperatures spike this dramatically this early, it disrupts the intricate timing that desert plants and wildlife depend on. Wildflowers may be triggered prematurely — or stressed into dormancy if soil moisture is insufficient. Migratory birds arriving on schedule may find their food sources out of sync. We’ll be tracking this closely in an upcoming piece on the desert wildflower season.
For residents, the risks are immediate. Older adults, outdoor workers, and those without reliable cooling are most vulnerable during a prolonged stretch of 100°F+ temperatures in March, when cooling infrastructure isn’t yet in its summer-season footing.
Riverside County typically publishes its cooling center network around June — that information isn’t live yet, but it’s worth bookmarking RivCoReady.org now and checking back as this heat event develops. If you need help finding resources in the meantime, Riverside County’s 2-1-1 helpline is a good first call. Typically, our local libraries act as cooling centers as well.
That this information isn’t available until later tells its own story about how quickly the season is shifting.
A Preview, Not an Outlier
What’s happening this week is not a freak event. The Palm Springs temperature record makes that clear: daily highs that once seemed extraordinary are becoming, decade by decade, the new baseline. Palm Springs summer record of 124°F in 2024. October’s national heat record. And now, 105°F+ in March.
An Extreme Heat Warning is in effect from 10 a.m. Wednesday through 8 p.m. Saturday, but the larger warning embedded in this week’s forecast has no expiration date.
Track your city’s records in real time using Climate Central’s Local Records Tracker. Check on your neighbors. And mark April 1 on your calendar — the snowpack data released that day will tell us a great deal about the water year, and the summer, that lies ahead.
This is what climate change looks like in March in the desert. The calendar says spring. The thermometer begs to differ.
Sources:
Climate Central – Climate Shift Index
Southern California Applied Climate Information System (local temperature data)
California Department of Water Resources (February Storms Provide a Much-Needed Boost but Statewide Snowpack Remains Below Average)
