Bold claim: The West set the pace for the warmest winter on record, while the East kept the country from a nationwide heat crown. And this is the part most people miss: the story isn’t just about temperature—the broader winter experience matters too. Here’s the rewritten, thoroughly updated version that keeps all key details intact and adds clarity for beginners.
Winter 2025-2026 delivered an extraordinary climate story. Across much of the western United States—from Southern California up to the High Plains and Northern Rockies—the meteorological winter (December through February) posted record-breaking warmth based on 131 years of data. In other words, the western half of the country experienced its warmest such winter on record so far.
While the West sweltered, the contiguous United States (all states except Hawaii and Alaska) still read as the second-warmest meteorological winter on record. Cooler conditions in the East helped prevent the nation as a whole from achieving a new all-time high. For further context, you can read about related records such as the notable event of an exceptionally hot winter temperature in South Texas during the same period.
Several long-running weather stations added new eras of warmth. Salt Lake City (with 152 years of data), Tucson (130 years), and Rapid City, South Dakota (114 years) all recorded their warmest winters in their respective histories. Phoenix, Arizona, shattered its own recent record by nearly 3 degrees, wiping out a previous record that had only stood for a year. Albuquerque, New Mexico, surpassed its prior warmest winter by 3 degrees, according to the Southeast Regional Climate Center. Helena, Montana, Las Vegas, and Lubbock, Texas were among other locales that reached record-warm status this winter.
But temperatures aren’t the only part of the puzzle. The severity of winter also depends on snowfall and overall winter impacts. To capture that broader picture, the Midwestern Regional Climate Center developed the Accumulated Winter Season Severity Index (AWSSI), which blends temperature and snowfall to gauge how mild or harsh a winter feels in practice. Weather sites across the western half of the country are reporting record mild winters under this index. It’s important to note that AWSSI isn’t limited to a strict winter definition; it reflects meteorological criteria that can span beyond traditional calendar months. So, for some locations, winter may still be ongoing even as March begins.
What does this mean in practical terms? A warmer, snow-light winter affects downstream seasons and water resources. With less snowpack, spring and summer conditions can shift, influencing flood risk, soil moisture, and water supplies in ways that ripple into the warmer months ahead.
What explains the West’s unusual warmth? A persistent ridge of high pressure parked over the western United States kept temperatures elevated and redirected the jet stream, causing storms to track farther north and pile up less snow in western mountain ranges. This pattern aligns with the negative phase of the Arctic Oscillation (AO), a global atmospheric circulation pattern tied to the polar vortex. When AO skews negative, the polar vortex weakens, allowing colder air to spill into the East while the West remains dominantly warmer.
Source-credits: Sara Tonks, a Weather.com meteorologist, notes this record-warm winter in her reporting. Tonks holds a bachelor’s and a master’s degree in Earth and Atmospheric Sciences from Georgia Tech, plus a master’s in Marine Science from Unity Environmental University.
If you’d like, I can tailor this rewrite to a different audience (e.g., social media caption, blog post, or academic brief) or add visuals and quick explanations of terms like AWSSI and Arctic Oscillation.
Would you prefer a more concise version for social media, or a deeper, sectioned explainer for a blog or report?
