March 2026: An Analysis of The Worst Snowpack Loss in 50+ Years for the Eastern Sierra

Overview

My friends...

In the below piece, I present an analysis of March 2026 snow sensor data in the Eastern and Southern Sierra. Over the course of March 2026, a significant, record breaking heatwave worked its way across the country, emaciating snowpack at all elevations across the Sierra Nevada, and the West at large. We suspected for quite some time that this would lead to historic snowpack loss, but now the numbers are in. It's just as bad as we thought!

March 2026 produced the worst snowpack loss on record across the Eastern / Southern Sierra. This analysis was conducted on data going back 50 years to 1976. At 30 out of 39 SWE-reporting stations, this was the single worst March for snowpack loss ever observed. At several more, it ranked #2 or #3 out of 40+ years.

The numbers are presented below:

A Month That's Supposed to Build Snowpack

March is historically an accumulation month in the Sierra. Over the last 50 years, the average Eastern / Southern Sierra station gains about 3.7 inches of SWE during March. March is typically marked by frequent storms due to shorter jetstream wavelengths.

This March was a different story, as the Polar Vortex disrupted the regular progression of Rossby-Waves, leading to a highly amplified but stationary pattern. Without frequent storms, the high March sun-angle began to work away at the snow.

Then, what happened in mid-march was a once every 5,000-10,000 year anomaly. A record breaking ridge parked over the Western US, taking down thousands of records across the country.

In March 2026, the average station in our analysis lost 8.9 inches of SWE. That's a departure of +12.6 inches from the 50-year norm...

Total SWE Lost: Station by Station

Below is every SWE-reporting station in our network, showing what March 1st looked like, what March 31st looked like, and how much water was lost. The Rank column shows where this March falls in the historical record. #1 means this was the worst March that station has ever seen.

Stations highlighted in red ranked #1 all-time. Data from CDEC and SNOTEL networks, 1976–2026. Stations with insufficient March 2026 data excluded.

The numbers are truly quite striking. Highland Meadow lost nearly 25 inches of SWE. Many other stations saw similarly epic declines. Only a few places, such as Leavitt Lake (frequently the snowiest location in the Sierra Nevada), still have commendable snowpack at 33" of SWE.

Stations That Melted Out Entirely

Several stations bottomed out completely over the course of the month. A few of them below:

• Monitor Pass (8,306 ft): 10.2" to 0.0" — 100% loss
• Willow Flat (8,220 ft): 8.3" to 0.0" — 100% loss
• Leavitt Meadows (7,200 ft): 7.1" to 0.0" — 100% loss
• Cottonwood Lakes (10,700 ft): 13.7" to 0.2" — 99% loss
• Caples Lake (7,920 ft): 10.0" to 0.2" — 98% loss
• Chagoopa Plateau (10,300 ft): 12.7" to 0.3" — 98% loss

Cottonwood Lakes sits at 10,700 feet and still lost virtually everything. Yikes!

Percent of Snowpack Lost

This winter had appeared to be saved by an incredible February storm cycle. We were near historical averages for snowpack at most stations on Feb 20th, and due to rain and warm temps started to decline after that date. Another way to comprehend this incredible snowpack loss is by a percent of SWE lost. Here are the stations that lost the highest fraction of their pack:

Showing stations that lost more than 70% of their March 1st snowpack.

18 stations lost more than 70% of their snowpack in a single month. The median station lost about 55% of its entire snow water content.

How Does This Compare to Every Other March?

Below, we compute the average departure from snow water change (in inches) for each station. This shows how much we lost relative to what we were expected to gain at each station according to climatological norms.

Sorted by departure from 50-year average. Green "gain" values represent the normal March behavior of adding snowpack.

Every single reporting station was worse than its 50-year average. The departures range from +8.5 inches worse (Upper Burnt Corral) all the way up to +30.3 inches worse (Highland Meadow).

Mammoth Pass

The numbers near Mammoth Mountain ski area may be of particular interest to this audience, here's some historical numbers since 1990 at Mammoth Pass (9,300 ft):

In most years, March adds 5-20 inches of SWE at Mammoth Pass. This year, it lost 7.6 inches. The previous worst March melt at Mammoth Pass in 36 years of record was 1997, where it lost 8.2 inches. March 1997 was actually the only month in Mammoth's history that recorded less snow than our 1" last month. They recorded 0.1" that year!

Elevation Didn't Help

While the losses are by far the most staggering at low and mid elevations, they were still significant at high elevations as well. Below are a few of the higher elevation snow sensor plots:

• Upper Tyndall Creek (11,500 ft): Lost 12.9" — #1 in 48 years
• Cottonwood Lakes (10,700 ft): Lost 13.5" — #1 in 51 years
• State Lakes (10,400 ft): Lost 16.6" — #1 in 46 years
• Chagoopa Plateau (10,300 ft): Lost 12.4" — #1 in 42 years

Bonkers!

The Bottom Line

The only March that comes close is 2015, the peak of California's historic drought. A few stations such as Ebbetts Pass (14.6" loss that year) or Huntington Lake experienced a similar melt in 2015. But 2015 was concentrated in certain areas. March 2026 was a region-wide catastrophe, setting records from Yosemite to the Southern Sierra, from 7,000 feet to 11,500 feet.

The snowpack was only slightly below average before March began. What's left now entering April is a fraction of normal (roughly 40% in our area). In fact, this ranks as the second lowest statewide snowpack ever recorded, at 18% of average.

Methodology

This analysis used daily Snow Water Equivalent (SWE) readings from 39 CDEC and SNOTEL stations across the Eastern Sierra, spanning 1976–2026 (51 years). March SWE change was calculated as the difference between the first and last available readings each March. Stations required at least 5 valid readings to be included for a given year. Historical averages and percentile rankings were computed from all qualifying years per station. Raw data sourced from CDEC (California Data Exchange Center) and NRCS SNOTEL networks.