Vermont Experienced One Of Its Warmest Mays On Record. Entire Spring, Too

May, 2024 was great for lilacs in Vermont, though they
came early and didn't stick around for long since it
was such a warm month.

Yep, May, 2024 Vermont climate figures are in, and we've had yet another really warm month. There's been a lot of those lately. 

 Burlington clocked in with its second warmest May on record, with a mean temperature of 63.3 degrees. That's 4.9 degrees above the "new normal." 

 I keep calling it the new normal because average is based on the aggregation of 30 years of data ending in 2020.  

That period was warmer than previous thirty-year intervals because climate change had already begun to take hold in the late 1990s and first two decades of the 2000s

In Burlington the only May in the past 140 years or so that was any warmer than this one came in 2015, which was just 0.3 degrees warmer than this one. 

What is now #3 on the list on warmest Mays isn't even close to being as warm as 2015 and 2024. 

Statewide the figures were pretty consistent, with most stations running somewhere around 4.5 degrees above our "new normal." 

Montpelier reported its eighth warmest May on record and St. Johnsbury had its fifth balmiest May. 

WARM NIGHTS

Following a trend I've seen frequently in the past couple of years, nights were especially warm in May. 

This was another month in which nights in particular were particularly warm, running a full 5.5 degrees above average in Burlington. 

The warmth was consistent. 

The coolest it ever got in Burlington during this May was 44 degrees on May 1. I checked back as far as 1900 - all I had time for, I'm afraid, and the closest Burlington came to such a warm monthly minimum in May came in 1904, when the coolest night reached 42 degrees. With this year included, there have only been four Mays that failed to at least get into the upper 30s if not colder in Burlington. 

All the other weather stations in Vermont had warm May nights this year. Except for Burlington, the chilliest morning of the month came Friday, May 31.  You'd normally expect the coldest readings of May to come near the beginning. Oh well. 

Unlike in most of the rest of the United States, there
wasn't much in the way of severe weather in Vermont
during May. There were some strong to severe
storms in a few Vermont towns on May 21, though.
Photo here is a storm moving into Georgia, Vermont that day.

Frosts and freezes in May are pretty common.  This year, we largely escaped that. 

Since 1900, 89 of the 124  Mays saw temperatures of 32 degrees or cooler, so you can see how odd a month's low of 44 is.  

In Burlington, May, 2024 joined the 90 degree club, as it got that warm on 22nd.  I looked back over 132 years of records in Burlington and found only 23 Mays that had a maximum temperature of 90 degrees or better. 

Probably with the help of climate change, 90 degree weather in May is beginning to get more common. Seven of the 23 Mays with 90 degree weather have happened just in the past quarter century. 

We've had a string of warm months. The last time we had a cooler than "new average" month was in November. 

RAINFALL

As with temperatures, precipitation was pretty consistent across Vermont. It was around an inch or so drier than normal in most places, give or take. The rainfall was on the light side, but it was frequent enough to keep things wet enough for spring blooms. Burlington had 13 days with measurable rainfall in May, all pretty evenly distributed through the month.

Overall, precipitation amounts were sort of in the middle of historical averages. Of the 140 years since records began in Burlington, 77 Mays were wetter than the one we just had and 63 were drier. 

May, 2024, blessedly, was not a month for weather extremes in Vermont, which was a nice break. While  repeatedly rounds of tornadoes, very severe thunderstorms, derechos, giant hail and flooding afflicted huge sections of the United States, we pretty much sat all that out. 

The only severe weather of note was in eastern Franklin County on May 21, when a severe storm threw down trees and power lines and tossed down a bunch of hailstones. 

The one other big event in the skies over Vermont during May wasn't exactly meteorological. Much of the nation - including Vermont - enjoyed a spectacular display of northern lights on May 10.  Leading up to the event, skies had been expected to remain mostly cloudy, so we'd miss out on the display.

But skies largely cleared, especially in the northern half of Vermont, leading to quite a show.  This was the second time this spring we lucked out with weather for a big celestial event. Skies over northern Vermont also remained mostly clear for the total eclipse of the sun back on April 8.

NEAR RECORD WARM SPRING

Meteorological spring runs from March 1 through May 31. In Burlington, it turned out to be tied with 1903 as the second warmest spring on record, with a mean temperature for the three months of 49.3.  The only spring that was warmer was 2012, with an average temperature of 50.3 degrees.

We've had a string of very warm springs. 2021 and 2023 are also in the top ten list of warmest springs, at least as measured in Burlington.