Are you dreaming of a White Christmas? The odds say no

If you are dreaming of a White Christmas for this year, then read on for some historical information on the occurrence of a White Christmas in central Indiana.

There are several ways to define a White Christmas. For the purposes of an historical look back, we’ll include a White Christmas as any day that has either at least a trace of snow on the ground, or experiences at least a trace of snow falling that day. In more general terms, we’ll define a White Christmas as any Christmas day that the Indianapolis area sees snow.

So what is the chance of at least a trace of snow falling at Indianapolis on Christmas Day?

Well, snowfall records on Christmas Day have been kept in the Indianapolis area since 1871. And in that 147-year period of record, a trace of snow (or more) has fallen 67 times. This could be equated to a 46 percent chance of at least a trace of snow falling on Christmas Day.

Our other possibility for a White Christmas would be if there was at least a trace of snow already on the ground.

That could be old snow from a week ago, or just the day before. Snow depth records don’t go quite as far back, and these were started in 1898.

And in that 120-year span, there has been at least a trace of snow on the ground on Christmas Day a total of 59 times. This could be equated to a 49 percent chance of at least a trace of snow on the ground on Christmas Day. For a more robust covering on the ground, there has been one inch of snow on Christmas Day a total of 34 times, which equates to a 28 percent chance to have this much snow on the ground on Christmas Day.

With both of our possibilities for a White Christmas explored, what then is our final chance?

What would our probability be of having either a trace or more of snow falling, or a trace or more already on the ground?

Since 1871, this has happened in a total of 85 times, where either the snow has fallen or already been on the ground. This results in an overall probability of 58 percent, meaning that six out of every 10 years, on average, will see either some snow falling or some snow already on the ground for Christmas Day.

The last Christmas that saw snow on the ground in the Indianapolis area was just last year in 2017.

The last time that snow fell on Christmas Day also occurred in 2017 when 0.1 of an inch fell.

So if a White Christmas is your dream, then you’ll probably take heart in these numbers. Much more often than not, there will be at least a few flakes around to greet us come Christmas Day.

However, highs in the 40s or higher are predicted clear up through next Thursday.

Greatest Snowfall

on Christmas Day

-- 5.9 inches in 1909

-- 4.4 inches in 1926

-- 3.3 inches in 1890

-- 2.6 inches in 2005

-- 2.4 inches in 1935

Greatest Snow Depth

on Christmas Day

-- 9 inches in 2004

-- 7 inches in 2002

-- 7 inches in 1909

-- 6 inches in 1995

-- 6 inches in 1935