NOAA’s Climate Prediction Center (CPC) has raised the probability of a very strong El Niño during late 2026, increasing the likelihood of characteristic El Niño impacts across the United States during winter 2026–27. Current seasonal guidance favors wetter-than-normal conditions across much of the southern tier and drier conditions across parts of the Northwest and northern United States, while above-normal temperatures are favored across much of the West, northern tier and parts of the East.
The probability of a very strong El Niño during October–December rose from 81% in CPC’s July assessment to 95% in August, with a 69% chance that the Relative Oceanic Niño Index (RONI) will reach at least +2.5°C (+4.5°F), a level that would exceed previous El Niño events in NOAA’s record dating to 1950. The strength and location of tropical Pacific warming and convection will influence how closely winter 2026–27 follows established El Niño patterns.