Winter 2017-2018

The winter of 2017-2018 featured some wild swings, from a very cold late December-early January to one of the warmest Februarys of all time. Let’s take a closer look at this volatile season, specifically December to February.

December 2017
Average High: 38.6 36th Coldest
Average Low: 23.7 33rd Coldest
Mean: 31.2 37th Coldest
Coldest High: 17 on 12/27/17
Coldest Low: 2 on 12/31/17
Warmest High: 60 on 12/4/17
Warmest Low: 47 on 12/22/17
32 or Below Highs: 10 11th Highest
32 or Below Lows: 27 5th Highest
Total Precipitation: 1.76″ 28th Driest
Total Snowfall: 8.1″ 23rd Snowiest
Average Snow Depth: 0.3″ 4th Lowest
Largest Daily Precipitation: 0.72″ on 12/23/17 31st Largest
Largest Daily Snowfall: 2.1″ on 12/30/17 32nd Largest
Highest Snow Depth: 3″ on 12/30-12/31/17 4th Lowest
Precipitation Days: 20 8th Highest
Snowfall Days: 15 8th Highest

December Records
Record High Minimum: 47 on 12/22/17. Tied for #1 Warmest Low for December 22nd. Tied with 2015.

January 2018
Average High: 35.4 39th Coldest
Average Low: 19.3 39th Coldest
Mean: 27.3 39th Coldest
Coldest High: 10 on 1/2/18
Coldest Low: -4 on 1/2/18
Warmest High: 60 on 1/11 and 1/22/18
Warmest Low: 52 on 1/11/18
32 or Below Highs: 14 11th Highest
32 or Below Lows: 26 6th Highest
Total Precipitation: 2.39″ 56th Driest
Total Snowfall: 10.5″ 38th Snowiest
Average Snow Depth: 1.4″ 15th Lowest
Largest Daily Precipitation: 0.66″ on 1/12/18 35th Lowest
Largest Daily Snowfall: 3.5″ on 1/12/18 29th Highest
Highest Snow Depth: 5″ on 1/16-1/17/18 6th Lowest
Precipitation Days: 26 4th Highest
Snowfall Days: 19 6th Highest

January Records
Record Low Maximum: 10 on 1/2/2018. Coldest High for January 2nd, beating the old record of 11, set in 1928.

February 2018
Average High: 47.3 7th Warmest
Average Low: 30.3 10th Warmest
Mean: 38.8 7th Warmest
Coldest High: 22 on 2/2/18
Coldest Low: 10 on 2/5/18
Warmest High: 77 on 2/20/18
Warmest Low: 60 on 2/20/18
32 or Below Highs: 5 6th Lowest
32 or Below Lows: 17 5th Lowest
Total Precipitation: 5.25″ 7th Highest
Total Snowfall: 6.0″ 43rd Highest
Largest Daily Precipitation: 1.23″ on 2/24/18 20th Highest
Largest Daily Snowfall: 4.4″ on 2/7/18. 17th Highest
Highest Snow Depth: 4″ on 2/7/18. 5th Lowest
Precipitation Days: 20 7th Highest
Snowfall Days: 10 13th Highest

February Records
Record Daily Snowfall: 4.4″ on 2/7/2018. Most snowfall for February 7th, beating the old record of 3.6″ set in 1895.
Record High Minimum: 55 on 2/15/2018. Warmest Low for February 15th, beating the old record of 53 set in 1954.
Record High Maximum: 77 on 2/20/2018. Warmest High for February 20th, beating the old record of 68 set in 1891 and 2016.
Record High Minimum: 60 on 2/20/2018. Warmest Low for February 20th, beating the old record of 49 set in 1930.

Winter (DJF only) 2017-2018
Average High: 40.4 28th Warmest
Average Low: 24.4 38th Warmest
Mean: 32.4 33rd Warmest
32 or Below Highs: 29 21st Highest
32 or Below Lows: 70 18th Lowest
Precipitation: 9.40″ 31st Wettest
Snowfall: 24.6″ 36th Snowiest
Average Snow Depth: 0.7″ 17th Highest (since 1948)

So overall, the winter was definitely warmer than normal, but not record-breaking, even with the extremely warm February. It was also wetter and snowier than normal as well.

Near white-out conditions on the evening of January 12th, 2018

Fall Weather Correlation to Winter Severity?

As we go into the winter season, it’s time to talk about how this one might end up. There’s a belief that fall weather is a good sign of how cold or warm winter will be. How true is that for Columbus? Also, what might any correlation mean for the winter of 2017-2018?

First, let’s just look at October temperatures.
The October normal mean temperature for Columbus is 55 degrees.

Between 1878 and 2016, there have been 47 Octobers that featured a mean temperature of 53.9 degrees or lower, what we’re considering a Cold October for the purposes of this comparison.
Of those 47 Octobers, 27 of the 47 had following winters that were colder than normal, or 57.4%, 13 had average temperature winters, or 27.7%, and the remaining 7 were warmer than normal, or 14.9%.
Interestingly, this category contains both the warmest winter on record- 1889-1890 and the coldest on record- 1976-1977- as shown by the chart below.

Next, we look at Normal Octobers, which are +/- 1 degree of the 1981-2010 Average of 55 degrees.
Between 1878 and 2016, there were 45 normal Octobers. Of those, 21 had colder than normal following winters, or 46.7%. 11 were followed by normal winters, or 24.4%, and 13 had warmer than normal winters, or 28.9%.

Finally, let’s look at warm Octobers, which are those with means of 56.1 degrees or higher. There were 46 Octobers with warmer than normal means since 1878. Of those, 18 featured following winters that were colder than normal, or 39.1%. Another 18, or 39.1%, were followed by average winters. The final 10 winters were warmer than normal. Here’s the graph.

So just based on the October mean temperature, Octobers that are colder than normal have a 47% higher chance of having a colder than normal winter than warmer than normal Octobers do. But is October a better indicator than November, a month that is closer to actual winter?

Colder than normal Novembers- 43.3 degrees or lower- included 78 Novembers since 1878. Of those, 38 or 48.7% had colder than normal winters. 21 (26.9%) had normal winters and 19 (24.4) had warmer than normal winters.

With the 38 normal Novembers, 43.4 to 45.4 degrees, there were 18 that had colder than normal winters, or 47.4%, with 11 normal winters (28.9%) and 9 warmer than normal winters (23.7%).

Finally, there were 24 warmer than normal Novembers since 1878- 45.5 degrees or higher. Only 6, or 25%, were followed by cold winters. An additional 9 (37.5%) were normal, while the last 9 (37.5%) were warmer than normal.

To reiterate, here are the ranked percentages of cold winters by the preceding October or November.
1. Cold Octobers: 57.4%
2. Cold Novembers: 48.7%
3. Normal Novembers: 47.4%
4. Normal Octobers: 46.7%
5. Warm Octobers: 39.1%
6. Warm Novembers: 25.0%

It should be no surprise that cold Octobers and Novembers have a stronger correlation to the following winters also being colder, with colder winters becoming increasingly unlikely as those months warm. Cold Octobers have a higher correlation than Cold Novembers, as well as Warm Octobers, but Normal Novembers have a slight advantage over Normal Octobers. Based on this, October actually has a stronger correlation to the following winter’s temperature mean than does November.

Going further, though, what about bi-monthly combinations?

Rank of Bi-Monthly Combinations and the percentage of colder than normal following winters, along with total years in sample:
Normal October/Normal November: 87.5% 8 Years
Cold October/Warm November: 57.1% 7 Years
Cold October/Cold November: 53.8% 26 Years
Normal October/Cold November: 48.1% 27 Years
Warm October/Cold November: 44.0% 25 Years
Cold October/Normal November: 38.5% 13 Years
Warm October/Warm November: 28.6% 7 Years
Warm October/Normal November: 26.7% 15 Years
Normal October/Warm November: 0.0% 8 Years

So a normal fall is clearly the best, but the sample size is not particularly high. Normal to Warm is unanimously warm, but again, it has a small sample size.

October 2017 has been overwhelmingly warm. While this wouldn’t normally bode well for a cold winter, each year is influenced by a multitude of factors.

For more general Columbus weather records, go here: Columbus All-Time Weather