OKLAHOMA CITY, OKLAHOMA — The first two weeks of September are on pace to end as the hottest on record across much of the Southern Plains and the lower Ohio Valley, according to an all-time temperature ranking analysis from BAMWeather covering the last 134 years of records. With numerous days of record heat still expected this week, forecasters say the Lower 48 as a whole is averaging more than 4 degrees Fahrenheit above normal for the month of September so far, one of the most anomalous starts to meteorological fall in over a century of recordkeeping.
Historic Ranking Places Much of Texas and Oklahoma at Number 1 Out of 134 Years
The BAMWeather map ranks the average temperature for the first two weeks of September at every location against the same stretch going back 134 years, on a scale where 1 represents the hottest such period on record and 134 represents the coldest. Across broad stretches of Texas and Oklahoma, the map shows a nearly unbroken run of rank 1 readings, meaning this year’s opening two weeks of September have been the hottest ever recorded at those locations in over a century of data collection.
Purple Dashed Corridor Traces the Hottest Zone From South Texas Into the Lower Ohio Valley
A purple dashed outline on the map traces the corridor experiencing the most extreme rankings, beginning across South Texas and the Rio Grande Valley, sweeping north through central and eastern Texas and nearly all of Oklahoma, then curving northeast through Kansas, Missouri and Arkansas before reaching into the lower Ohio Valley, including parts of Kentucky, Tennessee and southern Indiana. Nearly every location inside that outlined corridor is showing a rank of 1 through 3, underscoring just how widespread the record-setting heat has been rather than being confined to a single state or metro area.
Kansas, Missouri and Arkansas Also Posting Top-3 All-Time Rankings
Just outside the immediate Texas-Oklahoma core, the record heat extends firmly into the surrounding states as well. Kansas shows a mix of rank 1, 2 and 3 readings across its southern and central counties, while Missouri posts several rank 1 locations alongside readings of 2 and 3 elsewhere in the state. Arkansas follows a similar pattern, with rank 2, 3 and 4 readings across most of the state, placing it firmly among the top handful of hottest starts to September in the 134-year record.
Lower Ohio Valley Communities in Kentucky, Tennessee and Indiana See Top-5 Rankings
Farther northeast, the record-heat corridor extends into the lower Ohio Valley, where communities across Kentucky are showing rankings mostly in the 2 to 3 range, while parts of southern Indiana register as low as rank 1 and 2. Tennessee posts a slightly wider spread, with rankings mostly falling between 4 and 7 across the state, still firmly within the top handful of hottest starts to September on record even if not quite matching the extremity seen farther west and south.
Heat Rankings Moderate Toward the Great Lakes and Northeast
Outside the outlined corridor, rankings generally climb higher, indicating a less extreme, though still generally warm, start to the month. Much of the Midwest and Great Lakes, including Illinois, Indiana away from the southern border, and Michigan, shows rankings mostly in the single digits to low teens, still unusually warm historically but not challenging outright records the way the Southern Plains corridor has. The Northeast, including New York and New England, shows the most moderate rankings on the entire map, with some spots in northern Maine and upstate New York posting rankings in the 48 to 87 range, reflecting a far less extreme departure from typical early-September conditions in that part of the country.
Lower 48 Averaging More Than 4 Degrees Above Normal for the Month
Zooming out from the regional extremes, forecasters emphasized that the Lower 48 as a whole is running more than 4 degrees Fahrenheit above normal for September to date, a substantial nationwide departure for a single calendar month. That kind of widespread, multi-degree anomaly, layered on top of the outright record rankings across the Southern Plains and lower Ohio Valley, is what has pushed this year’s opening two weeks of September into record territory across such a large footprint of the country.
Numerous Days of Record Heat Still Expected This Week
Forecasters cautioned that this record-setting pattern is not finished, with numerous additional days of record heat expected across the Southern Plains and lower Ohio Valley through the remainder of this week. Residents across the outlined corridor, from South Texas through Oklahoma, Missouri, Arkansas and into Kentucky and southern Indiana, should expect the historically hot pattern to continue in the near term, with BAMWeather noting that additional details on how long the pattern lasts are available in the latest long-range video through its app.
