There are numerous physical characteristics of the atmosphere that can be measured to provide weather insight. Unquestionably, the data most commonly collected by meteorologists and amateur weather observers, and the one most often mentioned in casual conversation is temperature. On daily weather reports, the first order of business is noting how warm or cold it currently is, has been, and probably will be over the next several days. While the presence of sun, the threat of precipitation, and the strength of the wind may also be discussed, it is temperature that seems to dominate when the topic of weather is addressed.
Likewise, in presentations and lectures on global warming, temperature is of prime concern and useful in helping to document changes in climate. In the report Climate Change in the Champlain Basin sponsored by the Nature Conservancy and written by Dr. J. Curt Stager and Mary Thill, average temperatures were noted and analyzed from areas in the Champlain Valley and in the eastern section of the Adirondacks which drains into that basin. Additionally, other well researched national and global reports support the case for global warming partially based on the change in average temperatures at various locations over a long period of time. While average temperatures are useful for describing a climate and weather trends, they do provide some room for debate and discussion.
Average temperature is calculated by simply taking the high and low reading for the day and averaging them together. For example, a normal high temperature for mid January in the Central Adirondacks is about 24 degrees, and a normal low is about 2 degrees. This yields an average temperature of 13 degrees.
Any increase in wind speed and cloud cover over the past few decades could suppress the nightly radiational cooling of the atmosphere and result in warmer minimum temperatures. Even with a slight breeze, the air does not cool as it does when perfectly calm. A thin layer of overcast can likewise limit heat loss to space and prevent the temperature from falling, as can the presence of an air mass with high humidity.
If the temperature only drops to 10 degrees on that mid January night, it would produce a daily average temperature that is 4 degrees warmer than normal, despite the same high temperature of 24 degrees.
When I first moved to the Adirondacks in the very early 70’s, I heard on several occasions that 15 nights during the month of January should be at, or below zero. That seemed to be the case until the 80’s. Over the past decade I can’t recall any year when we have had 15 nights in January with subzero mercury readings. (In noting weather records, I realize that the 50’s, 60’s and early 70’s were exceptionally cold. That may have been a function of the “mini-nuclear winter” that occurred after more than 500 nuclear weapons were tested in the atmosphere during that cold war era, or the result of some natural phenomena, and perhaps that saying was only valid for that period when our climate was unusually cool.) On the other hand, I do not believe that daytime temperatures in winter, or during any other season, have risen at all over the past 40 years.
In Stager and Thill’s report, it was noted that June and September are the months that have experienced the greatest increase in average temperature for the Adirondack region. It would be interesting to note if this was the result of an increase in both daily highs and lows, or just mainly in the lows.
An increase in just the low temperatures at this critical time of the year, when the last and first frosts of the season typically occur, would have a profound impact on the length of the growing season, and affect the ability of the region to support non-native plants.
I believe that a warming trend is in progress however, I don’t think that our daily maximum temperatures are much higher. I also believe that our nightly minimums have risen noticeably. As I have stated in my other articles, I do not keep any weather records of my own, nor have I spent the time and effort analyzing available records to ferret out this information. I only speak from 40 years of personal experience noting temperatures and weather events in the Saranac Lake region.
The study sponsored by the Nature Conservancy was a great step in the right direction, however, much more needs to be done. It takes countless hours of sifting through volumes of weather records and analyzing them in numerous ways in order to gain better insight into this extraordinarily complex problem. I wish those individuals that want to explore this issue the very best in trying to secure funding for their research, as valid scientific investigations, rather than undocumented ramblings, are desperately needed to determine what may happen to nature here in the Adirondacks.