Something Weird And Warm Is Going On With Vermont Septembers

A little hard to see in there, but a bumblebee is seem
here enjoying a white rose on a warm September
Sunday morning in St. Albans, Vermont. Recent
Septembers in Vermont have grown sharply warmer. 

 As we all know, we are in the midst of a long spell of oddly warm, dry September weather in Vermont. 

Sunday was the third day in a row of 80 degree temperatures, with at least four more in a row coming.  

It hasn't rained in Burlington since a sprinkle on September 9, and there's a chance it won't rain again for another 10 days.

 That depends on whether a weird little possibly subtropical storm expected to hit the Carolinas Monday can throw enough moisture our way to set off a few sprinkles toward the middle of this week. 

Spells of September weather like this used to be rare in Vermont, but in recent years, it's gotten far more common.

Thanks climate change, the top 10 lists of warmest months throughout the calendar has a number of recent years clustered in those lists, at least as measure in Burlington.  It's just warmer than it used to be, so we're more likely to have near record warm months thrown in. 

But September is ridiculous.  The ninth month of the year has taken a sharp turn toward becoming an extension of summer, especially in the last decade or so.

The top five warmest Septembers have all occurred since 2015. Until recent years, the warmest September in Burlington had an average of 65.4 degrees, set in 1961. Now, the warmest year is 67.4 degrees, set in 2015.

Even the recent Septembers that didn't make the top ten warmest list have been balmy.

Septembers with an average temperature of under 60 degrees used to be the usual. Only 40 out of the 100 Septembers between 1900 and 1999 had an average temperature of over 60 degrees, as measured in Burlington. 

Then it changed. All Septembers since 2010 have had an average temperature of over 60 degrees, and only one September since 2000 has fallen short of a 60 degree average.

Recent Septembers have also featured very long dry spells, longer and hotter than the one we're having now. The warm to hot, and rainless spell in September, 2017 was as extreme as they get. That month featured 20 consecutive days with absolutely no rain at Burlington. 

That dry spell culminated in a seriously whacked out heat wave. Until 2017, the latest 90 degree temperature of the season was on September 16, 1939. But on September 24-27, 2017, Burlington saw four consecutive days in the 90s. 

The 2017 autumn heat extended through October, which became by far the warmest on record in Burlington. 

In 2015, each of the first nine days of September were over 80 degrees, and three of those got above 90 degrees. In 2018, there were five consecutive days of temperatures of 85 or more from the fourteenth through the 18th. 

Our current warm, dry September - as toasty as it is - will probably not be the warmest on record. I question whether it will even make it into the list of top ten warmest.  But once again, this September is not your grandfather's early autumn month.