At a Glance
- October may have a split personality across the U.S.
- The month is certain to start out very warm for most, except the West.
- However, that pattern is expected to flip, based in part on past strong El Niño Octobers.
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October may start out more like a summer month over much of the United States, but that pattern may change, according to the updated outlook from The Weather Company, an IBM Business, and Atmospheric G2.
What changes are in the latest October outlook? The updated temperature forecast has been warmed up markedly in the central and Northeast.
Temperatures will be most above average throughout the Plains and upper Midwest. Warmer than average conditions will extend into most of the Northeast, as well as into the Rockies.
The only areas that could skew a little cooler than average are the Florida Peninsula and parts of Northern California and Nevada.
What's driving this outlook? The month will start with a pronounced "omega block" weather pattern that will pump warmth into much of the central and eastern U.S., while the Great Basin and West Coast is relatively chilly.
But that pattern could change, and it could do so as soon as the first full weekend of October, according to computer model guidance. That change could bring temperatures back down closer to average in the central, eastern and southern U.S., while warming up the West.
That's the big question with this outlook. When will this pattern change happen and how persistent will it be through the month?
There's also an El Niño connection. According to Todd Crawford, director of meteorology at Atmospheric G2, Octobers during El Niños tend to be cooler than average over much of the country, except the West Coast and southern Florida.
Those are two large wild cards in this outlook that could lead to a much different outcome.
What is average for October? High temperatures continue their downward trajectory during this core fall month. Highs averaged over the whole month across the northern tier are generally in the 50s and 60s.
Farther south, highs still remain quite warm with 70s and 80s most common.
Mornings also quickly trend cooler. Lows drop into the 30s and 40s for much of the northern U.S. from the Northwest to the Midwest and Northeast.
Lows in the 50s and 60s are common for most of the South and Southwest. Mild mornings continue in Florida, where morning temperatures in the 60s and 70s are typical in October.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
