How Our Big Vermont Heat Wave Compared With Past June Hot Spells

Thunderheads billow into the sky over St. Albans Bay,
Vermont during the peak of this past week's heat wave on
Wednesday.  The scattered showers and storms probably
prevented actual high temperatures from getting even
higher than they did

 Before the just-ended heat wave, I predicted this would be among the biggest June hot spells on record for Vermont.   

Sure enough, this was a biggie, but not the most extreme we've seen.

The most notable record was the minimum temperature in Burlington on Wednesday, June 19 of 80 degrees. That ties the all-time record for highest minimum temperature for any date in Burlington.

The persistence of the heat in Burlington overnight, was incredible. The temperature rose above 78 degrees from a little before 9 a.m. June 18 until a little after 3 p.m. June 20 when a strong thunderstorm dropped the temperature to 72 degrees. 

 The high temperature Wednesday in Burlington was 96 degrees, four degrees short of the record for the date and the all time record high for the month, also set on June 19 back in 1995. I have a feeling that we would have made it closer to 100 had the sun stayed consistently out all day. 

But the air was so humid it generated numerous showers and storms, which helped keep temperatures down by a few degrees. 

I'd still rate our recent hot spell as worse than the one in 1995. The average temperature in Burlington on June 19, 2024 was 88 degrees and due to a cooler night back then, the mean temperature on June 19, 1995 was half a degree cooler. 

And we only had two days in a row with temperatures over 90 back in that hot spell in 1995. 

 I did find a June hot spell way more intense than the one this past week.  Probably the worst June hot spell on record came in June, 1946. It would have been the second longest heat wave on record if one day had not fallen just short of 90 degrees.

On June 24-30 the highs in Burlington were 90,92,94,89,93,96,93.

Unlike this year, June, 1946 was chilly until that late month heat wave.

TRENDS

Overall, Burlington has had a grand total of 82 heat waves since the 1880s. A heat wave here is defined as three or more consecutive days in which the temperature reaches 90 degrees or more. 

This was only the 16th heat wave entirely within the month of June. Climate change is likely contributing to more hot weather in June than in past decades. 

Temperatures above 95 degrees used to be rare in June, happening in only a handful of years prior to this century. With Wednesday's high of 96 in Burlington, that makes four of the past five Junes making it to 96 degrees in Burlington. 

Junes with multiple days going to 90 or above seem to be increasing, too. Including this year, I found 13 Junes in the past century in Burlington with at least four days in the 90s. Seven of those Junes have happened since 1999. Only three of them were before 1983. 

More 90s this June are certainly possible, but unlikely. The best chances of it happening are this coming Wednesday, but that's really iffy.

There's plenty more time for additional hot days in July and August, though. 

The record for the most 90s in a single year still stands at 26, back in 1949. It would be a real tall order to break that record in 2024.