December 2020 had been forecast to be wetter than usual in the Chemainus Valley and, even though it didn’t start out that way, the original outlook proved true with total rainfall winding up almost 50 per cent higher than normal for the month.
“The rainfall turned out to be rather spotty during the first half of the month, with the heavier rain and snow not starting until the second half,” explained Chris Carss, a volunteer weather observer/recorder for Environment Canada at his Chemainus home.
With rainfall above normal overall, the total snowfall, by contrast, was about 30 per cent below normal, according to Carss, but persisted long enough after a Dec. 21 storm to leave some patchy snow cover of one centimetre or less for Christmas Day.
“Technically, it wasn’t a White Christmas which requires an even snow cover of at least two centimetres, and some areas of the Chemainus Valley may not have had any snow cover at all on the 25th,” he added.
“However, it was the third White or ‘Whitish’ Christmas in the past five years for those who got some of the white stuff, which is no mean feat for the Chemainus area or anywhere else on the West Coast. It was also the second time this year that a change in meteorological seasons from fall to winter coincided closely with its corresponding astronomical or calendar season, the previous time having been in late June with the change from spring to summer.
The other seasonal changes saw the meteorological spring and fall both arriving about 10 days after the calendar changes.
Oddly, December was also a bit sunnier than usual despite the extra rain, Carss noted.
“The slightly reduced cloud cover in December was highly productive. Temperatures were about a degree above normal, but this fell within the ‘standard deviation’ for what can be considered normal for the time of year.”
The mean daily maximum temperature for December was 7.6 degrees Celsius (normal 6.4 C) and the mean minimum came in at 3.5 C (normal 2.4 C). The extreme maximum of 12.5 C occurred on Dec 9 and the extreme minimum of -1.5 C on Dec. 24.
There were seven days of mostly or partly sunny conditions. That’s two above the normal of five days with sunshine.
Of the 24 mostly cloudy days, precipitation occurred on 20 of them. The normal days with precipitation is 21.
Total rainfall amounted to 307.6 millimetres (normal 226.9 mm) and total snowfall 13.2 cm (normal 19.4 cm).
At Keith Rush’s Foster Point Road residence on Thetis Island, he recorded rainfall of 250.1 mm, way above the 137.4 mm from December 2019. The average December on Thetis produces 157.0 mm.
The total precipitation for 2020 on Thetis was 1,336.9 mm. By comparison, the total for 2019 was a mere 795.2 mm.
The New Year has started with copious amounts of rainfall, but should start to taper off around Jan. 8, according to Carss, with spotty rainfall that should be characteristic during the middle of the month. But heavier rainfall is expected to return near the end of January, he added.