David Epstein: Is winter finally in our rear-view mirror?

"The upcoming pattern looks quite mild."

Chris O’Connell practiced his daily meditation and breathing exercises at Victory Park in Dorchester during last week’s mild temperatures. –Craig F. Walker / The Boston Globe

It was chilly across Greater Boston this morning, but there are milder days in our future.

The strong March sunshine and relatively mild afternoons over the past couple of days may have prompted you to start thinking that winter is over. Of course, declaring the end of deep cold and snow can be dangerous for meteorologists — the weather has been known to throw us curveballs. However, the upcoming pattern looks quite mild, and odds are we have seen the last of the accumulating snow this year.

Folks will always remind me that there was a big April blizzard back in 1997, and it snowed the second week of May in 1977. Last April brought a couple of days of accumulating snow early in the month and even some snow showers the second half of the month. April 2018 was one of the chillier we have seen in quite a while with the average temperature nearly three degrees below average. Although the sun was strong, the temperatures were not what most of you would consider comfortably mild.


First 70-degree day?

Over the next several days, a flow of air from the south will help boost temperatures well into the 60s. There’s even the chance that a couple of spots could notch a 70-degree day Saturday. It can be quite difficult for Boston to hit 70 degrees this time of year unless the wind is west-southwest, but it’s certainly not impossible. Usually though, any flow of air off the ocean will prevent temperatures from getting that warm as the ocean water is still very cold. It’ll take several more months of warming for Boston Harbor to get warm enough so a sea breeze doesn’t bring a deep chill.

If we do reach 70 this weekend, it wouldn’t be that unusual. The first 70-degree day for the past couple of years has actually occurred in February, but we didn’t get there last month.

On average, the first 70-degree day occurs in early April. —NOAA data

The warm weather might get you excited to put out some plants, and there are plenty of varieties that will thrive in the upcoming weather. Lots of cool-weather vegetables and things like pansies and senetti do great things this time of year. Remember though, a frost is still possible in most areas until at least next month. Notice on the map below how much of Cape Cod as well as Greater Boston does not see a frost beyond the middle of April.

The average date of the last frost in spring is in April for much of the Greater Boston area. —NOAA Data

There are a lot of signals in the atmosphere pointing toward temperatures off the average. Indeed, the long-range outlook for April has much of the eastern third of the United States in warmer temperatures. This doesn’t mean it won’t be cold or that we won’t get any snow, it just means that when we look back at April 2019, it’s likely to have averaged above normal.

Check back with me on May 1, and we’ll see how accurate all of this was.

Enjoy the warmer temperatures!