Record Heat Will Expand Out
By Monday, highs in the mid 80s to near 90 degrees are expected for parts of the Great Lakes and Northeast. Daytime temperatures are expected to be 15 to 25 degrees above average, so it certainly won't feel like autumn. Humidity levels will thankfully be lower, and nighttime temperatures won't be excessively high. Across the Southeast for next week, average highs will range from the mid 80s to around 90.
September Heat, Explained
This ridge is not only expansive, but it extends well up into Canada. It is extremely unusual for this time of year to see the jet stream so far to the north.
The exaggerated ridge across the eastern US will gradually break down over the second half of next week, and the high temperatures in the east will come down.