Welcome to December! The holiday season is upon us — and so is winter.
December 1 marked the beginning of “Meteorological” winter, which runs from December 1 through February 28 (29th in leap years.)
What kind of weather should we expect this December?
Climatologically speaking, December is our third coldest and third snowiest month of the year. Our 30-year average December monthly temperature is 35.6°F, ranking just below January (31.4°) and February (34.7°) on the list.
The liquid precipitation average for December is 3.73”. Now, when I say “liquid,” that means a mixture between rainfall and snowfall. However, the number from snowfall is the amount of liquid we receive when the snow is melted.
As far as snowfall, December is our third snowiest month of the year on average. Over the last 30 years the average snowfall in December is 4.1”, which falls behind to only January’s 7.7” and February's 6.7”. However, if you take our last 10 years, the average is just 2.96”.
Our snowiest December ever happened back in 2010 when we had a whopping 16.6”. That month brought three separate days with 3.0” of snow or more. That culminated in our second to last White Christmas, which we will touch on later this month. The December with the least amount of snow was in 1931 when we didn’t have any recorded snowfall.
As you can see in graph below, the last time we actually had saw an above average month of snow here in Cincinnati was way back in 2013 when we saw 10.4”. Since then, the following eight Decembers have combined for just 11.6”. Safe to say, snow in December has become a rarer feat. You may notice that 2015 has a number of 0.0", because we didn't receive any measurable snow. However, we did have a "trace" which is basically a dusting.
So, what should does that mean we should expect this December? Well, we are already a few days into the month of December and so far it is way too early to define a trend. However, the first five days of the month has led to below normal temperatures by 2.5 degrees as well as below normal precipitation. But as mentioned, that sample size is way too low to make generalizations.
The Climate Prediction Center’s (CPC) monthly outlooks (issued on November 30) show the month of December will be wetter than normal.
December's temperature outlook calls for a colder than normal month. But that doesn't mean we'll be below freezing more often, just colder than the average temp of 35.6°F.
Colder than average temps and above average precipitation might sound like more snow, but recent history doesn't show that to be the case. In our last 30 years, 15 Decembers were colder than normal, but only nine of those had above average snowfall. The last time above average snowfall happened was in 2013. That is a hit rate of 60%, which isn’t a slam dunk.
Another thing to remember, that we are in a “La Niña” phase this winter. There have only been four occasions where we have had snowier than normal Decembers in a La Niña, the last of which came in 2010.
Sad to say snow lovers — and I am one myself — it doesn’t line up to be a snowier than normal December even though it looks like we will see colder than normal temperatures. One can hope that changes.
