Climate Comment for December 2025The Early Winter See-Saw Continues
Submitted by Bill Caulfeild-Browne
Although the month was just about normal for temperature, it surely didn’t feel like it. The wintry blast that began on November 30th continued with a vengeance, giving us nearly 30cms of snow in the first week. And yet, ironically, we barely got a white Xmas because the mercury fluctuated so much.
The middle of the month saw highs well above freezing from the 16th to the 25th, the warmest being 7.2C on the 18th. That day also gave us 18mm of rain. It wasn’t until the last two days that temperatures dropped back into negative double digits of -10.1C and -10.7C respectively. The coldest day, though, was the 14th at -11.1C.
Measuring precipitation at this time of year is fraught with difficulty. The moisture content of snow is highly variable. While one millimetre of water is generally thought to yield one centimetre of snow, in truth it could be much more or less. Light and fluffy snow might be much deeper than one centimetre, while a centimetre of heavy wet snow will contain more that one millimetre of water. I use the 10:1 ratio but am aware it’s at best an estimate. Based on that, our “rain” for the month was 74mm, This is about normal for December.
2013 holds the record for the last 30 years at 1086mm, while 1998 came in at just 564mm.
Tobermory escaped some of the worst snowfalls that afflicted the Province. Northern Ontario had snow depths roughly twice normal. Kapuskasing had 170cm on the ground by month-end. Southern Ontario got its share too – Toronto Pearson got 178% of normal snow.
On both December 9th and 18th major ice and snow storms paralyzed areas to our north and south, and on Boxing Day six to eight hours of freezing rain resulted in hundreds of accidents, hydro outages and downed trees. An even worse storm hit central Ontario on the 28th, causing flight cancellations, 110 kph winds and multiple road closures. My wife and I were lucky to have flown to warmer climes on the 27th – the one day that saw normal flight operations.
As I write this on January 8th we are once again warming up, with a forecast of thawing for the next few days. This is probably our usual January thaw, but variability is the norm in this era of climate change.
