As my previous post suggested, since returning to New England after 24 years away I have found the relationship between temperatures and seasons oddly dislocating. The previous post explored how summer temperatures have changed since my childhood, and why I am experiencing them the way I am. In this post, I look at changes to fall and winter in Worcester. This post not only explains what is happening to winter in this part of New England, but also fleshes out something remarkable: the annual structure of temperature in this part of the world has changed in profound ways since my childhood. Where I grew up in a world where wintery temperatures lasted much longer than those of summer, today winter and summer temperatures are nearing parity on an annual basis. Fall transitions into winter much later than when I was a child, but winter ends only a little earlier than it used to. At least when it comes to temperature, Worcester (and New England more broadly) is a very different place than the one in which I grew up.

Let’s talk about fall. Since returning to New England, I have found this season particularly disorienting. I expect it to become cold much sooner than it does, and find myself increasingly unsettled by the temperature across October, November, and December. I have clear memories of a much colder fall, and a much harsher transition to winter, than what I experience now. On November 12, 1990, my high school soccer team won the NH state championship on a frozen pitch in 27-degree Fahrenheit weather (it was 23 degrees Fahrenheit that night in Worcester) 1. I’m not crazy in coming back to that memory. During my childhood, the average high temperature on November 12th was 44.5 degrees Fahrenheit, with average lows of 30.9, so that game was a slight outlier. Today, that average is 51.5 degrees Fahrenheit, with average nighttime lows of 33.2…which would make that game a larger outlier, but also as that average nighttime low is above freezing, it also means that a frozen pitch would be a very unusual event. Further, the onset of winter temperatures, signaled by the first hard frost, has changed. The first hard frost now comes an average of 16 days later than when I was a child (previously October 24th, now November 9th). In other words, even if the game is played on a freakishly cold night, it is unlikely that soccer players in NH will have to play 2 a State Championship game on a frozen pitch again.

If I feel bit adrift in the fall and early winter, I tend to come into port in January, February, and March. This is despite the fact the data suggest that the change in winter is even more striking than that in fall. The period characterized by hard frost, between the date temperatures first drop to 28 Fahrenheit or lower and the last day temperatures reach this point, lasted an average of 173 days each year during my childhood. Today, the average for this period is 148 days, a mind-boggling 25 days shorter. The figure below compares the period of winter temperatures, as marked by the first and last hard frost, across the year as it was when I was growing up and today. As noted above, today the first hard frost is delayed by more than two weeks relative to my childhood. The last hard frost arrives nine days earlier in the year (previously April 16th, now April 7th).

The distribution of winter weather across the year in my childhood and today. The graphic shows how the winter ends earlier, and starts later, than it used to.

Why, then, would I feel most at home in the temperature in January, February, and March? The answer also lies in the data: once we get past December, the temperatures within winter start to converge with the temperatures I knew growing up. We used to average 113 days per year that reached 28 Fahrenheit or lower. Now the average is 93 days, an incredible decline of 20 days in just over 25 years. However, the relative proportion of total days below 28 Fahrenheit in winter has not changed much. When I was growing up, an average of 65% percent of winter days reached temperatures below 28F. Today, that average is 63%. Most of those days are concentrated in January and February. The average temperature in the month of January might be 2.53 degrees Fahrenheit warmer than what I grew up with, but it is still only 25.2 degrees! Similarly, while February is also warmer (by 1.41 degrees Fahrenheit), the average temperature is 27.5 degrees Fahrenheit, still below the hard frost temperature. Today, March is actually colder than in my childhood, though only by .14 degrees. All of this means that these months feel quite similar to those I experienced as a child.

It’s the transitional seasons in and out of winter (particularly fall), the margins of the winter itself, that have seen the greatest changes. The transition to spring, however, is gentler on me than Fall. April, while today an average of 1.21 degrees Fahrenheit warmer than in my childhood, has not radically departed that past experience. The spring in New England is still long, still muddy, and still unpredictable. After April, May warms up considerably, and we are into my earlier discussion of changes in summer.

People, like plants and other animals, have a degree of photosensitivity – an expectation of what things should feel like temperature-wise at a given length of day and angle of the sun. Nothing has changed with regard to the length of day or the angle of the sun, but for much of the year the temperature in New England no longer aligns with these other factors in a manner I understand. The chart below captures these changes across the year, illustrating how the character of daily temperatures in New England has changed enough to render this place nearly unrecognizable.

What it shows is that while nearly every month has seen some temperature increase, every month has seen an increase in the average minimum temperature, and that increase is larger than the increase in average high temperature. Put another way, the difference between daytime and nighttime temperatures is compressing, whether gently as in April, or dramatically, as in October and December. The connection between hours of sunlight, the angle of the sun, and temperature that I developed for myself playing in the woods behind my house in the 1970s and 1980s is an artifact of an environment that no longer exists. For someone to understand what I am talking about in a visceral way, they have to be around my age (or older), and to have spent enough time outdoors in daylight to have developed this sense.

The figure below visually represents the radical change in the structure of temperatures across the year since my childhood. It is a to-scale representation of the average duration of the “hard frost” and “summery” 3 temperature periods, both when I was growing up and now. The intervals between the seasons are also to scale. It shows that in the space of the past 25 years, where I live has gone from a winter-dominated temperature signature to one approaching parity between winter and summer temperatures. When I was growing up, wintery temperatures lasted an average of 52 days longer than summery temperatures each year. Today, wintery temperatures only last 13 days longer than summery temperatures. The shift is staggering, and explains my general dislocation when it comes to temperature, particularly in the fall.

Summer and winter temperatures laid out across an annual scale. The shift toward annual parity between summer and winter is clear.

One thing is clear: my children are growing up with a very different sense of the relationship between the amount of sunlight, its angle, and temperature than I did. They live in a different world than the one in which I grew up. Another thing is sure: given the inertia in our climate, my children will have some version of the experience I am describing at some point in their own lives. I worry, however, that they will not get to their mid-40s before this awareness sets in. Rates of change are not slowing, and there is little to suggest that we will stabilize global temperatures (a prerequisite to stabilizing local temperatures) in their lifetimes. I’ve lost a connection to the world that I loved, and I will not get it back. I was gone too long to make the subtle adjustments to my perceptions necessary to overlook this change, and after four years I still feel dislocated every fall. The terrible part of this is that we’ve already ensured that our children will have this same experience. The question is not if, but when.

Notes:

  1. Yes, I had to look the date up. I had no memory of that the game being on a Monday night
  2. The key term is play, which I use advisedly here, as I was a reserve striker on that team and never got into that game. It’s not fun to watch a championship game from the bench. It’s worse when you are freezing
  3. Recall from my previous post that I am defining “summer-like” somewhat arbitrarily as the period between by the first day of the year over 25 Celsius (77 Fahrenheit) that was followed by consecutive days of temperatures above 70 degrees and closed by the last day over 25 Celsius at the end of several consecutive days over 70 degrees