Since 2015 much of the northwestern U.S. has been getting colder in winter. This is tied to the increased frequency of the westward-focused polar vortex (a high-altitude ribbon of cold air circling the Arctic) pattern and coincides with stronger negative phases of the El Niño/Southern Oscillation (ENSO), a key global climate driver. This helps explain recent cold waves in places like Montana, the Plains and even Texas.
https://phys.org/news/2025-07-polar-vortex-patterns-shifting-winter.html