December 1917 through January 1918 still stands today as the coldest and snowiest December-January period ever recorded in Louisville, Lexington, Bowling Green, and several other locations across southern Indiana and central Kentucky. The 49 inches of snow that buried Louisville during those two months beats the 2nd snowiest December-January by more than a foot and a half!

The pattern that would bring the Ohio Valley such a miserable winter actually started to take shape before summer was over. Strong Canadian high pressure entered the northern Great Plains on the 8th of August, bringing temperatures in the 30s to Montana and Wyoming. Several additional highs followed through the rest of August and into September. On September 11 record lows were set in central Kentucky that still stand today: 42° at Lexington and Frankfort, and 44° at Louisville.

The parade of Canadian highs intensified in October, with snow accompanying the cold in the Great Lakes. Every station in Michigan reported snow during the month, with an even 12 inches falling on Ironwood on the Wisconsin border. On the morning of the 9th the freezing line dipped all the way down into Arkansas. A terrific surge of frigid air during the last few days of October brought sub-zero temperatures to the Rockies, sub-freezing temperatures to Texas and Louisiana, and middle 30s were reported in the Florida Panhandle.  On the 30th Louisville had a high temperature of only 34° and Lexington didn’t make it above 30°, which is still the coldest October high temperature ever recorded in both cities. The month remains the coldest October on record at Louisville (#3 at Lexington, #5 at Frankfort, and #9 at Bowling Green).

A break in the weather came for the first 3 weeks of November, with generally mild conditions. A brief shot of cold air came through around Thanksgiving, followed by another brief warm-up into early December.

Then the cold returned with a vengeance.

A huge dome of high pressure gathered over northwest Canada during the first week of December and began to slide southeast on the 7th. Meanwhile, low pressure was forming over Texas and beginning to head to the east.  On the 8th the low strengthened as it crossed the Tennessee Valley while the Canadian high pushed into the United States, spanning the entire length of the Great Plains all the way to the Texas coast. The low passing by to our south brought copious amounts of precipitation to the region, and the frigid high coming in from the northwest caused that precipitation to be in the form of very heavy snow. Over a foot of snow fell on the lower Ohio Valley, including 16.4” of snow recorded at the Louisville Weather Bureau station and about 10” at Lexington. The heavy snow on the 8th was accompanied by strong winds, gusting to 42mph at Louisville and 37 mph at Lexington, resulting in massive drifts.

Transportation was made extremely difficult by the heavy snow, resulting in shortages of fuel and other supplies. Country roads were impassable for several days and some rural schools were closed for a week or more. Young livestock suffered greatly and there was considerable loss, especially among pigs. Quail were reported to have starved and frozen.

Though temperatures started out around 30 degrees at the start of the day on the 8th, by midnight that night the mercury had fallen to -1° at Louisville and -4° at Lexington. On the 9th the monstrous high pressure system pushed into the southeast United States while the snowy low soared into New England while strengthening even further. Caught between these two systems, winds were even stronger on the 9th than they had been on the 8th with sustained winds up to 49 mph at Louisville and 50 mph at Lexington, and gusts to 52 mph at both locations. To add to the misery, those winds occurred while temperatures were mostly in the single digits, resulting in wind chills (using the modern formula) of 20 to 30 degrees below zero.

On the 10th wind speeds were “only” in the teens and 20s, but the high temperature at Louisville was 7°, and Lexington didn’t make it past 6° after a morning low of nine degrees below zero.

From the 8th to the 17th there was at least one station somewhere in Kentucky or Indiana reporting a sub-zero low temperature. Lowest temperatures around the area during the cold wave:

Records set at our main climate sites December 8-11, 1917 that still stand today:

Much of the length of the Ohio River froze over completely. By the 11th the ice was solid at Madison and gorged at Evansville, and by the 17th the river was solid at Cincinnati. At its mouth at Cairo, Illinois, the ice conditions exceeded in severity anything in the memory of the oldest inhabitant. The Kentucky and Licking rivers froze over as well.

A warm-up took place during the ten days leading up to the Christmas holiday, causing the snow pack to melt away. The warmth peaked on the 24th with highs in the 50s, and there was no snow on the ground Christmas Eve as a light rain fell.

It would be a month before we would see 50s again.

Another massive Canadian high pushed a cold front through southern Indiana and central Kentucky late Christmas Eve and brought another round of bitter cold to the region. Two to four inches of snow fell on southern Indiana and north central Kentucky on the 25th, helping to set the stage for the cold temperatures to come.  By the morning of the 30th a second, reinforcing high came in and was centered just northeast of Lexington at dawn. In southern Indiana temperatures bottomed out at -14° at Madison, -20° at Paoli, and -19° at Salem and Scottsburg. In central Kentucky the coldest readings were -16° at Bardstown and Frankfort, -19° at Junction City, and -20° at Taylorsville.

A hundred years later, December 1917 still stands as the 3rd coldest December on record at Louisville and Lexington, #4 at Frankfort, and #6 at Bowling Green.

A few more inches of snow fell on the 1st and second of January 1918, and with the exception of a brief respite on the 5th and 6th, colder than normal conditions continued through the first 3 weeks of the new year. As a matter of fact, even after the blistering cold of early December, citizens of southern Indiana and central Kentucky hadn’t seen the worst cold of the season yet.

On the 11th yet another dome of incredibly cold air that had organized in northwest Canada pushed into the northern Plains and Rockies while strong low pressure developed rapidly near New Orleans. On the night of the 11th and into the 12th the low continued to deepen and became quite powerful as it shot through the Tennessee and Ohio Valleys to the Great Lakes while the Canadian high nosed as far south as the Texas coast.

Though the 11th started off near the freezing mark, the low traveled just to our east and joined forces with the western high to pull frigid air down from Canada. As the low deepened, those winds grew stronger…and stronger…and stronger. By evening sustained winds were in the 20 to 40 mph range across southern Indiana and central Kentucky, combined with blinding snow that had started falling around lunch time and intensified in the afternoon.  As darkness fell the blizzard raged, with gusts to 52 mph at Louisville and 44 mph at Lexington. At 7pm in Louisville winds were sustained at 30 mph with a temperature of 13°.

The twelfth day of 1918 “was probably the coldest and most disagreeable day experienced in a century” (Monthly Weather Review), or at least since the intense cold of January 1, 1864 (Climatological Data).  At 7am, winds were blowing at 20 to 30 mph while the temperature at Louisville was fifteen degrees below zero and Lexington was fourteen below. Using the modern calculation, that gives a wind chill around 45 degrees below zero!

Though the snow had ended and the sun came out, the wind continued to roar throughout the day at speeds of 20 to 40 mph with higher gusts. The temperature rose to only -2° at Louisville and -3° at Lexington.  January 12, 1918 is still one of only two days in both cities’ histories during which the temperature stayed below zero all day.

After the storm of the 11th-12th abated, intense cold continued. Every day from the 12th to the 22nd the daily high temperature at Louisville was colder than the normal low temperature (using 1981-2010 normals). Heavy snows fell during this time as well, including 11.2” at Louisville on the 14th-15th
accompanied by winds gusting to 45 mph.

Transportation was practically paralyzed, including the inter-urbans and streetcars. In Louisville on the 14th three people were killed when two inter-urban cars collided, and the next day four people died when a snow-laden roof collapsed. Fuel shortages added to the misery, and schools were closed for several days. In northern and western sections of Kentucky some rural farmers were snowbound for up to two weeks.

Lowest temperatures January 10-23:

The amount of ice on the Ohio and middle Mississippi rivers surpassed anything that had been seen before. At Cairo pedestrians were able to walk across the Ohio River to Kentucky, a feat unknown to even the oldest inhabitants of the region. 

Though there was one more cold snap in early February when some locations dipped below zero on the 4th-5th, the remainder of the winter was relatively mild. On February 28 record highs were set that still stand today, including 75° at Lexington and 77° at Louisville.