May Weather In Vermont Was Simultaneously Gorgeous, Smoky, Disastrous And Very Weird

The intense May 18 freeze killed this set of leaves on a 
tree in Huntington, Vermont. The freeze also caused 
extensive damage to fruit crops throughout Vermont,
and defoliated numerous trees. 

I didn't get a chance to do my monthly climate summary for May yesterday, so I'll give a shot today. 

What a weird month! 

Most people who aren't extreme weather geeks are probably thinking what a gorgeous weather month May, 2023 was. And they're right! I would rate more than half the days during the month as clear or mostly sunny,

Temperatures on most days were comfortable, with low humidity and a nice breeze.  On paper, too, it was nice. The average temperature for the month was not that far from what is currently considered average.

But we saw some glaring nuances that made the month really kooky. 

FREEZE

The most obvious example is that killer freeze we had on May 18. Temperatures in most of Vermont that morning were between 18 and 28 degrees. Plants had blossomed prematurely amid what had been a very warm spring. 

Just six hours after those cold temperatures, it was back to sunny and pleasant. But that one frigid, record cold night caused an agricultural disaster in Vermont and surrounding states. Apple orchards, vineyards, blueberries, strawberries and other crops suffered severe damage. Some trees had their leaves frozen off, and those oaks, ashes, locusts and sumac are yet to recover. 

Although there has been no official declaration yet, I'm pretty sure at least some counties in Vermont will be declared a disaster area due to the extensive crop damage. 

SMOKE

Wildfire smoke from Canada mostly obscured the evening
sun over St. Albans, Vermont on May 8.

Then there was the the smoke.  Most of Canada was very oddly warm and dry during May. Large wildfires broke out in Alberta and British Columbia early in the month. By late month, those wildfires had spread to Ontario, Quebec, New Brunswick and especially Nova Scotia.

Since over the air over Vermont most of the time during May had come from Canada, smoke was almost a constant presence in the atmosphere. Most of the smoke was aloft, so it didn't cause much in the way of health problems for us. 

But it did haze over the skies, and sometimes the mountains. By my count, no fewer than 14 days featured some haze in the sky because of that smoke. 

RAIN PROBLEMS

Some nice, soaking rains arrived in late April and the first three days of May, which seemed to set us up for a nice drought-free early summer for a change. 

Not so fast. 

The rain shut off on May 4 and never really came back. Burlington's rainfall total for the month was just under two inches, which was about 1.8 inches below normal, and bad enough. But only 0.64 inches fell after May 3, a time period which should have seen a good three inches of rain.  That explains why your garden was so dusty by Memorial Day. 

Most other places in Vermont were about two inches shy of normal during May. 

Average temperatures for the month had an interesting slant, too. The trend this year so far has generally been nights being much warmer compared to average, while daytime highs weren't as far above normal.

By the end of May, we really had to irrigate gardens as
very dry weather had taken hold, starting around May 4. 

May had the opposite setup.  The past month had a bigger range between high temperatures and daily lows. Pretty much every reporting station in Vermont had somewhat warmer than average high temperatures but decidedly cooler than normal overnight lows. 

Rutland was especially notable in this regard. Nights in May averaged 4.6 degrees cooler than normal. And 18 nights during May in Rutland got below 40 degrees, with seven of those nights getting to or below freezing.  

Officially, the overall average May temperature in Burlington was 57.6 degrees.  That is 0.8 degrees cooler than what is now regarded as the normal average temperature for the month. But that's based on the average of the 30 years ending in 2020.

Because of climate change, that period is definitely warmer than the historical 20th century average.

If you compare how May, 2023 did with what the average was in say, around 1980, the just ended month was really 2.5 degrees above what was considered normal back in the 20th century. 

Which means we're still on a streak that began on February, 2022 in which every month since then has been warmer than the 20th century Burlington average. Even if a few of those months were slightly cooler than the new, warmer "normal" they're using now. 

Who knows, maybe June will break that streak.  The first two days of June have seen record heat in Vermont, but long range forecasts suggest we could be cooler than average for the next two weeks.

That's not a guarantee of course, but it's something to watch.