The Scott County Chamber of Commerce used to have a marketing line for September: Sizzlin’ September.
The terminology was retired a few years ago, but September 2019 really is sizzling, and the heat shows no sign of abating anytime soon.
So far, September 2019 is featuring temperatures that are 3.5 degrees above average, as measured in Oneida, thanks to nighttime temperatures that are dropping to near normal for this time of year each night. But once the sun rises each morning, temperatures have been anything but “near normal.” The average afternoon high this month is 88 degrees, about 6.5 degrees above normal for the month of September.
If it seems like the hottest temperatures of summer have been this month, it isn’t just your imagination. June’s average daily high was 81.6 degrees, which was slightly below normal. July’s average daily high was 85.5, which is very normal. And August’s average daily high was a slghtly-below-normal 84.7 degrees.
Technically, fall doesn’t begin until September 23, the fall equinox. But from a meteorological perspective, fall begins on September 1, and most homeowners close their swimming pools on Labor Day weekend early in the month. This year, though, summer is hanging on with a vengeance.
Consider this: Prior to September 1, Summer 2019 had featured just six days with temperatures at 90 or above in Oneida, and the overall high was 91 degrees, on July 21 and August 20. But September has featured five days with temperatures at 90 or above, more than any other month this year.
The hottest temperature was Wednesday, September 11, when temperatures topped out at 95 degrees. That was a record-high for the date in Oneida. Record-high temperatures were also recorded on Friday, 92 degrees, and Saturday, 94 degrees.
In a normal year, the average daily high doesn’t get out of the 70s by September 15. Yet, the National Weather Service at Morristown forecasted a high of 88 for Oneida on Sunday, with temperatures forecasted to be in the upper 80s for most of the week ahead.
Weather enthusiasts have complained that the autumn season is slowly being eroded by extended summers, and it’s becoming increasingly hard to argue with that theory. If September 2019 winds up setting a heat record, it’ll beat out the previous hottest September of 2018 — meaning back-to-back years of record-breaking temperatures in September, which is a transitional month into the fall season.
It’s much too soon that September 2019 will be record-setting. For one, official weather records measure monthly temperatures only by the overall average, a combination of daytime and nighttime temperatures. And when the near-average nocturnal temperatures are factored in, September 2019’s heat hasn’t been as impressive in Oneida. Plus, half the month remains, and temperatures generally cool quite a bit between the first of the month and the end of the month. Currently, the average temperature in Oneida this month is 72.6 degrees. That’ll almost certainly go down as the month progresses, and it’s already lower than the September 2018 average of 73.4 degrees, which is the record.
But if we were talking an average of daytime highs, September 2019 would certainly be in strong contention to set a record. The current record for average daytime highs during the month is 76 degrees, set in 1973. While September 2019’s average daytime high will almost certainly cool as the month continues, it is currently at 87.9 degrees, smashing the existing record.
September heat waves aren’t at all uncommon. In fact, there have been several Septembers in Oneida that have featured more days in the 90s than September 2019 — including 2016, which featured eight days in the 90s; 1999, which featured six days in the 90s; 1998, which featured a record eight days in the 90s; and 1980, which featured eight days in the 90s. But September 2019 is winning the prize for relentless heat. Even when temperatures haven’t reached the attention-grabbing 90-degree threshold, they’ve been well above normal on a consistent basis.
That’s likely to be the continuing theme as September closes out. Oneida may very well stay below 90 degrees for the rest of the month — that, in fact, would be considered likely — but NOAA’s Climate Prediction Center is forecasting significant chances of above-average temperatures all the way through the end of the month.
Just for fun, the latest recording of a temperature reading of 90 or above in Oneida is October 4. That occurred back in 1973, and is the only instance of 90-degree temperatures in Oneida since records-keeping began here in the mid 20th century.
So when will things change? Unfortunately, this pattern of hot and dry is going to continue its death-grip on the region until one of two things happen: a significant tropical storm blows up in the Atlantic and disrupts things, or a strong low pressure system to our north that will drag in a cold front capable of beating down the Southeast ridge. As long as neither of those two things appear poised to occur, forecasters are probably right in forecasting much above normal temperatures to continue for at least the next couple of weeks.
If this pattern persists long enough, you’ll start to see comparisons to 2016 thrown out. That was the year of heat and drought throughout the fall months that led to the worst wildfire season East Tennessee has ever seen — including the deadly Gatlinburg fire. In fact, September 2019 is on pace to be even drier than September 2016 was.
The hot and dry start to the season could also put a damper on the fall colors as the foliage begins to turn next month. And the question many will ask: what does a hot start to fall mean for the upcoming winter season? It’s too soon to say with any certainty what Winter 2019-2020 holds in store, but based on both the way September is playing out and the overall atmospheric synoptic setup and sea surface temperatures — along with forecasts of what’s ahead — the safe bet is that if you like long stretches of cold and snowy weather, you’re going to be disappointed.