Before last year, 70 degrees in February seemed almost an impossibility here in Southern New England. Although the sun is stronger, it’s still the middle of winter and a May-like afternoon nearly a month before St Patrick’s day is well, kinda nutty.
Prior to February 2017, Boston had only reached 70 degrees in February once, in 1985, since record-keeping began in 1872. Then, last year, we not only saw 70 degrees once, but that day was sandwiched between a high of 68 and a high of 69, making for three incredibly mild afternoons more typical of May. Fast forward to this week, and we once again are going to reach near or even above 70 degrees in February as part of two days of extreme warmth.
Maximum One-Day Mean Max Temperature for Boston Area
Averages in New England are made up of extremes, and our average first occurrence of 70 degrees typically won’t be until about April 8. What often happens is we get a 70-degree day in April, followed by cooler weather, followed by increasingly more regular warmer weather. The normal high temperature doesn’t go above 70 until the final days of May.
The reason for the extreme weather this year is a powerful high-pressure system off the coast of the United States pumping warm and unusually moist air into the region. This setup is typical for the middle of summer. It’s the reason why we have hazy, hot, and humid days in July and August.
On Wednesday, when some people will be out running in shorts, others will be lamenting about the shrinking winters and the abnormal climate. While one or two occurrences of 70 degree weather at the wrong time of year doesn’t mean the climate has changed, a changing climate does increase the likelihood these things will happen more and more in the coming decades.
This is school vacation week, and temperatures across ski country won’t reach 70, but they will get well above freezing. That means shrinking snow cover, to the detriment of the winter sports industry. Additionally, too much warm weather to early can adversely affect the maple sugar industry, as well as farmers.
There is good news. Unlike a couple of years ago — when a mild fall was followed was by brief extreme February cold that wiped out the entire peach crop — this year’s cold start to winter allowed our plants to go dormant. I don’t expect this brief spell of spring to affect this year’s crop. Of course we don’t know what lies ahead in March and April, but for now we should be OK.
Our weather will remain active over the next seven days, with several chances for precipitation as temperatures return closer to seasonal normals. This means we could see some wintry precipitation, especially away from the coast, in the coming week. As of now, the beginning of March looks cool and potentially stormy.
The record high temperature for Wednesday is 63, set in 1906, and it’s likely we’re going to break it by a lot. There’s no doubt I will be outside enjoying the winter break on Wednesday, but in the back of my mind I’ll also be thinking about what future winters may look like.