Climate Comment for January 2025
limateSubmitted by Bill Caulfeild-Browne
January seemed like a pretty brutal month, particularly when compared with the same month last year. But in truth, it was still warmer than normal by 1.2C. What seemed unusual was the frequent wide variations in temperature. Most of the first week was quite mild, then it got cold for a few days before swinging back to mild – almost a January thaw if it had lasted longer. The third week was cold once again, while the last was comparatively warm.
The see-saw effect was due to our being right on the line between the polar vortex and warmer air to the south. Even so, our coldest night, the 21st, only got down to -13.6C, a far cry from the high negative teens we might expect. The warmest day was the 18th when we reached +3.2C.
The big story of the month was wind and snow. The unusually warm open waters of Lake Huron excelled in bringing us lake-effect snow and we sure got plenty. It’s hard to translate water measured in millimetres into accumulated snow in metres for two reasons. First, heavy wet snow has a high water content, while “dry” flakes have relatively little. Second, high winds can transport snow almost horizontally so it doesn’t land in a gauge.
My gauge registered only 45 mm of moisture because it’s exposed to winds right off the lake. The station at the airport showed 81mm. It all depends on your location.
What we know is we got snow on 20 days which built up to some impressive drifts. The airport, again, measured as much as 33 cms on the ground – where there was little drifting. The climax came just a few days before month-end. Winds whipped up to 60 km/hr here and were worse to our south. Highway 21 has been almost constantly closed, and for two days we were marooned here in Tobermory too. Hwy 6 was simply impassible.
There is very little ice on Lake Huron and only on about one-third of Georgian Bay, so until we get some protracted cold weather to create ice, we can expect the lake-effect snow to continue.
Last year I felt sorry for snow removal operators who had hefty insurance bills to pay, but very little paying activity. This year I’m sure things look better. It’s an ill wind that blows nobody any good!
