What regional temperature and precipitation anomalies are expected in north america for dec 2025 and jan 2026
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Executive summary
NOAA’s Climate Prediction Center and other climate agencies favor a weak La Niña persisting into Dec–Feb 2025–26, with a transition to ENSO‑neutral becoming likely in January–March 2026 (CPC gives about 61–68% chance of transition timing; IRI and CPC probabilities for La Niña in DJF are roughly 53–55%) [1] [2] [3] [4]. Forecasters expect above‑normal temperatures across much of the U.S. Southeast, Northeast and parts of the West Coast for DJF, increased precipitation for the Pacific Northwest and parts of the Midwest, and below‑normal precipitation for much of the Southern Tier including Florida and California — but model and dynamical uncertainties (stratospheric forcing, North Pacific anomalies) leave room for cold intrusions, especially in Canada and the northern U.S. [1] [5] [6].
1. La Niña is the headline driver — but it’s forecast weak and possibly short‑lived
Multiple operational trackers and outlooks characterize the tropical Pacific state as La Niña–favored into boreal winter, then shifting toward ENSO‑neutral by early spring 2026; CPC’s official text and associated ENSO discussions place the transition window at January–March 2026 with roughly a 61–68% chance, while IRI’s multimodel mean gives La Niña a plurality for Dec–Feb near ~53% [2] [3] [4]. That matters because a weak or waning La Niña produces a much noisier signal for regional anomalies than a strong event, lowering forecast confidence for specific month‑by‑month outcomes [1] [4].
2. Temperature expectations: warm South and East, colder risks in Canada and the northern Plains
CPC’s DJF temperature outlook favors above‑normal conditions across much of the U.S. East Coast, Southeast, Gulf Coast, Texas, the Southwest, and California [1]. Several regional analyses and reporting note a pattern with colder anomalies focused over interior Canada and occasionally the north‑central U.S. when Pacific and stratospheric patterns align; independent forecasters highlighted the possibility of a colder start to winter driven by North Pacific anomalies and potential polar vortex disruptions, which would produce episodic cold waves into December and possibly January [6] [7] [8]. Thus the dominant expectation is seasonal warmth for large population centers in the U.S. South and East, but alternative scenarios — notably a stratospheric warming or North Pacific‑driven circulation change — can force colder-than‑normal conditions in parts of Canada and the northern U.S. [1] [7] [6].
3. Precipitation: wetter Pacific Northwest and parts of Midwest, drier Southern Tier and parts of California
CPC and consulting meteorologists point to above‑normal precipitation prospects for the Pacific Northwest and into portions of the Midwest and Great Lakes, while much of the Southern U.S. (including Florida) and California are favored to be drier than normal — a pattern broadly consistent with La Niña tendencies [1] [5]. WMO’s global seasonal update also increases probabilities for above‑normal rainfall in northern parts of North America in their NDJ outlook graphics, but the report emphasizes spatial variability and competing oceanic influences [9]. Localized departures (e.g., wet December storm or a prolonged dry spell) remain possible because the La Niña signal is weak and other factors (North Pacific SST anomalies, atmospheric blocking) can tip the balance [9] [6].
4. Stratospheric/Polar Vortex signals complicate the month‑to‑month story
Forecast commentary from independent long‑range analysts flagged a rare early stratospheric warming/Polar Vortex slowdown that could produce colder early winter conditions and persistent cold events into January if realized [7] [8]. Official NOAA/NWS discussion material recognizes that polar vortex and North Pacific teleconnections alter the typical ENSO fingerprint — available sources show the polar vortex is a critical uncertainty and that tropospheric response can vary, meaning cold outbreaks are plausible even with a generally warm forecast state [10] [7].
5. What this means for December 2025 and January 2026 specifically
Synthesis of CPC and related product messaging: expect a higher probability of above‑normal temperatures for much of the U.S. Southeast, Northeast and parts of the West in the December–February window, with above‑normal precipitation favored in the Pacific Northwest and parts of the Midwest and below‑normal precipitation across the Southern Tier [1] [5]. However, December could see early cold intrusions in Canada and the northern U.S. if the polar vortex or North Pacific pattern evolves toward disruption — independent forecasts emphasize that possibility and longer‑range uncertainty [7] [6]. For January, forecasters expect ENSO to be shifting toward neutral, reducing the ENSO‑driven signal and increasing the relative influence of other circulation drivers [2] [3].
Limitations and competing viewpoints: operational CPC/IRI products present a cautious, probabilistic picture centered on a weak La Niña and largely warm anomalies across the U.S. [1] [4]. Independent long‑range analyses argue for a stronger cold potential tied to stratospheric events and North Pacific anomalies [7] [6]. Available sources do not mention exact numerical anomaly maps for every region for December 2025 vs. January 2026 separately; they provide seasonal DJF guidance and process‑level reasons for regional deviations [1] [9] [4].
If you want, I can extract the specific CPC maps and probability fields for December and January individually from the CPC or WMO pages cited here and summarize the geographic probability ranges and confidence levels for each month.