The National Oceanic and Atmospheric Administration’s Climate Prediction Center is leaning warm for the week of October 19-25, 2026, across most of the Lower 48 states. Only two regions clear the highest bar: southern California and the Northern Plains, where the chance of landing in the warmest third of normal tops 60%. Forecasters rated their confidence at 4 out of 5, and that number describes the pattern forecast, not the thermometer.
A warm week matters because late October is when many regions expect the first real chill. A prolonged warm spell delays the peak of fall color, pushes back the start of home heating, and keeps outdoor seasons going longer than usual in places that are normally closing them down.
What a tercile outlook actually measures
Climate Prediction Center outlooks do not forecast a temperature. They divide the historical record for a given place and week into three equally sized groups of cold, near-normal and warm outcomes, then assign a probability to the most likely group. When the center says odds are better than 60% for above normal, that means a better than 60% chance that the week lands in the warm third of its own local history. The other two groups share what is left, and with equal chances the odds sit at one in three each.
That framing is why a 60% figure is more impressive than it sounds. Because a coin toss between three groups gives each a 33% chance, a reading of 50% already means the forecast tools have moved far from the climatological default. The figure also says nothing about how warm warm is. A week can be in the upper tercile by a single degree or by ten, and the outlook map treats both the same.
Peak odds in the 8-14 day window
The period of October 19-25 is the center’s 8-14 day outlook, issued on October 11, 2026 by forecaster Daniel Barandiaran. In that discussion, the highest chances of above-normal temperatures are over southern California and the Northern Plains, at better than 60%, with 50-60% odds over much of the Central and Northern Plains. The sibling forecast for October 17-21 is sharper still, and the discussion states that “Odds exceed 50% across the West and the Northern Plains, and top 60% for southern California and over the northern High Plains.” The Climate Prediction Center discussion is the document behind both maps.
The warmth is not uniform. The discussion leaves lower odds of above-normal temperatures in parts of the Southern Plains and in the Northeast and Mid-Atlantic. That second region is already flagged in a separate week-two product: the center’s probabilistic hazards outlook, also issued October 11, carries a slight risk of much below normal temperatures in parts of the Northeast, northern Mid-Atlantic and Appalachians on October 19, with possible first frosts or freezes.
The ridge and El Nino behind the forecast
The discussion points to a large-scale pattern of positive 500-hPa height anomalies across the contiguous United States, meaning a ridge of high pressure aloft that favors warmth, with one or more shortwave troughs crossing the country. For the six-to-ten-day period the blend is weighted 25% to the American GEFS ensemble mean, 50% to the European ensemble mean and 25% to the Canadian ensemble mean, and the discussion says the three agree on the pattern. The 8-14 day period carries weaker troughing but a similar overall setup.
The tropical Pacific is also in the background. The same discussion describes active tropical Pacific convection as at least partially due to forcing from El Nino, and the center’s October 8 ENSO discussion keeps an El Nino Advisory in place, saying a strong-to-very strong event is likely through January-March 2027. A tropical link to a single week of weather is loose, so it is best read as context rather than a cause.
Wetter in the south, drier elsewhere
Precipitation is a separate call. For October 19-25 the center favors above-normal precipitation for the Desert Southwest, the Southern and Central Plains and the Gulf Coast, and favors below-normal precipitation for the Northeast and parts of California. The six-to-ten-day outlook is drier still, with below-normal precipitation indicated for much of the rest of the contiguous United States outside the southern tier. Confidence in the rain signal is lower than in the temperature pattern, because the discussion notes wide spread among precipitation forecast tools in the later period.
The warm lean also fits the longer view. The center’s September 17 seasonal outlook favored above-normal temperatures for October through December across most of the western, northern and eastern United States, with equal chances from the southern Rockies across the southern Plains into the Lower Mississippi Valley. Readers who want to see the daily maps can open the center’s 8-14 day outlook page, which updates each afternoon and will show whether the signal firms up or fades before the week arrives.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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