Vermont March Warm Spell Nice, But Odd Temperature Spikes Increasingly Common This Time Of Year

I took a screen shot of some of my
saved iPhone images from last 
spring for some color. Spring
heat waves have been getting
more frequent and more intense
in Vermont, a likely sign of 
climate change.

 Starting today, at least some parts of Vermont will see highs in the 60s for five consecutive days.  That's unusual for this time of year, of course. But it's becoming less unusual.

 There's an increasing trend toward very odd temperature spikes in late February, March and April across the Green Mountain State.  This is all a likely sign of climate change at work.

This week's weather is another example of how some pretty wildly warm spring weather has become much more routine in Vermont. 

The strong spring sun can bring temperatures to brief, summer-like levels this this time of year on relatively rare occasions.  Back in 1945 and 1946, temperatures reached the 80s in Vermont in late March.

After that, we went another 30 years before another 80-degree day came on March 30, 1977.  The frequency of such hot days slowly continued to ramp up.

On March 15-17, another big early season heat wave hit.  It hit 83 degrees in Rutland on March 16, 1990, easily the earliest 80 degree reading on record in Vermont. 

 In Burlington, temperatures soared to 78 degrees,  on March 16, 1990. At the time this was by far  the hottest for so early in the season. The 72 degrees on March 15 that year was also easily the earliest 70 degree reading on record for the season.   At the time, I considered that an unbreakable record, but wait for the spoiler. 

Then, just nine years later, another boffo March heat wave hit. Burlington tied its all-time record high for March at 84 degrees. The all-time Vermont wide record for hottest March day was set in southeastern Vermont, with 88 degrees. 

Four years later, it was an April heat wave that broke records.  Until 1976, it had never been known to be at or above 90 degrees in April in Vermont. That year, 1976, a very strange hot spell brought temperatures to 90 degrees and above on April 18 and 19. 

That was widely considered to be something you can't beat. But sure enough, on April 17, 2002, it was 90 degrees in Burlington, taking the place as the earliest 90 degree reading.

More spring records kept falling. In 2012, an unprecedented early season heat wave graced Vermont in mid-March. At at time of year when normal high temperatures are in the low 40s, daily high temperatures in Burlington on March 18-22 were 76.79. 80, 81, 81.  That helped March, 2012 become by far the hottest on record for Vermont. 

In 2016, Burlington set a record for earliest in season 70 degree reading on record on March 9.  That record was shattered a year later when a winter hot spell brought temperatures to 72 degrees on February 25, 2017.  That shattered the record for hottest February day in Burlington by nine degrees.

In 2018, another similar late February heat wave brought temperatures to 69 in Burlington, 70 in Montpelier and 71 in Rutland.

All these stats I threw at you boil down to one statement. Late winter and spring ain't what it used to be in Vermont. 

Once upon a time, this forecast for five 60 degree days in a row in March in Vermont - like we have now - would have been almost unprecedented. With climate change, such warmth has practically been relegated to boring early spring conditions.