Posted by:SteveDa1, 03:10 PM GMT del 12 Maggio 2012
F = 1.8C + 32
Winter's cold shots are less extreme today It doesn't just seem like winters are not as cold as they used to - it's a fact. The coldest three months of the year - December, January and February - are not only getting warmer overall, they are also experiencing weaker (not necessarily shorter) cold snaps. I'm aware that I'm only looking at one particular area but I'm certain that if I broadened my field of view I'd obtain similar results. If it's happening in my own backyard chances are it's unfolding elsewhere in this country and continent and that it's probably happening in most places. Also, to graph data for each city would be very time-consuming and would make this hobby a grind. Finally, although I cannot conclude anything, assumptions are always verified with every graph I make.
The following graph shows the numbers of days (or nights, if you prefer) where the low drops below -10C, -20C and -30C with trend lines showing the obvious decline.
I like to keep it short and let the graphs tell the story... because they really do tell a thousand (...or more) words!
Trend of days with lows less than or equal to -10C: -1.3/decade
Trend of days with lows less than or equal to -20C: -1.1/decade
Lows below -30C are becoming extremely rare with the last occurrence in the winter of 1993-1994. An event that used to happen once in while, is now almost non-existent.
Click on the following images for a larger resolution.
The number of days with a high above the freezing mark is also on an obvious trend - on the rise.
Trend of days with highs above 0C: +0.7/decade
Also, older folks who were born in the 40's may actually be right about the lack of snow (compared to the past) today. This, however, is very regional and does not indicate anything in any other area across North America