January 22-31, 2024

January Ends Anomalously Warm

After a mid-month freeze, the final week of January was characterized by widespread anomalous warmth. Average temperatures were generally 4-8°F above normal across the lower Midwest; 10-15°F above normal along and north of the I-80 corridor; and 15-20°F+ above normal across the Upper Midwest (Figure 1). Yet again, Minnesota and Wisconsin were the center of above-normal temperatures, with statewide departures of 20°F and 16.5°F above normal, respectively. Iowa averaged 12.2°F above normal, Michigan was 12°F above normal, and Illinois was 9°F above normal. The least anomalous departure was out of Missouri, which still averaged 6.5°F above normal, followed by Kentucky at 7.5°F above normal. Indiana and Ohio were in the middle of the pack, with departures of 9.5°F and 10.3°F, respectively.

Minimum temperatures averaged as much as 25°F above normal across northern Minnesota for the week, and some locations saw departures higher than that (Figure 2). International Falls, Minnesota set minimum temperature records two days in a row, January 25-26, bottoming out at 28°F both days. This was 35°F above normal. Eau Claire, Wisconsin set daily minimum temperature records every day from January 24 to January 29, and all records were 25°F or more above normal.

Maximum temperatures were less anomalous, but not by much. In Minnesota and Wisconsin, most maximum temperatures were 12-16°F above normal (Figure 3). Through the mid-Mississippi River Valley, departures were 3-6°F above normal, with departures of 6-10°F through Indiana and Ohio. The temperature rose above 50°F in International Falls on January 31, which was a first for any day in January. Minneapolis reached 55°F on January 31, which was not only a daily record but only the third time it hit 55°F or above in January since records began in 1870.

Healthy Rains, Snowfall Deficit

Precipitation was plentiful for the lower Midwest, but not so much north of Chicago. The gradient in precipitation was extreme, with parts of southern Illinois, western Kentucky, and southern Missouri receiving over 3 inches of rain for the week while much of Minnesota saw no precipitation (Figure 4). Most of this fell as rain, as temperatures rose gradually through the week. Initially, a system early in the period brought freezing rain, which caused significant icing in Missouri, where a fire truck slid down an icy road. In parts of Indiana over two inches of precipitation fell during the final week of the month. Indianapolis ended the month with almost 5 inches of precipitation, well over the normal January total of 3.12 inches. In Michigan, Detroit measured 5.25 inches of precipitation by the end of the month, making it the wettest January in 151 years of records, while Grand Rapids had its 2nd wettest January on record. On the opposite end of the state, in Houghton, only 0.38 inches of precipitation fell, making it the 10th driest January on record.

Snow was nearly nonexistent for most of the region. Michigan was the only state where appreciable snow fell during the period, and it was generally limited to the eastern half of lower Michigan, where 3-6 inches of snow fell through the week (Figure 5). One round of snow came at the beginning of the period, bringing 4-6 inches of snow to the Saginaw area and freezing rain to Greater Detroit. The other low pressure system came at the end of the period, on January 30, and generally brought 1-2 inches of snow to the entire I-75 corridor from Detroit to Saginaw. The lack of snow through the second half of the month led to historically low snow water equivalent values by January 30, with most of Minnesota, northern Wisconsin, and Michigan’s Upper Peninsula within the tenth percentile.

Drought Removals and Rising Rivers

Major rain allowed for the removal of drought conditions from many areas south of I-70. Severe drought (D2) had already been removed at the beginning of the period from the Ohio River Valley, and by January 30, all moderate drought (D1) was removed from Illinois, Indiana, and Kentucky (Figure 6). Some moderate drought remained in Missouri. Major rainfall missed Iowa, Minnesota, and Wisconsin, where conditions generally remained unchanged, except in western Iowa where extreme drought (D4) was removed.

Rapidly rising temperatures, heavy rains, and residual river ice caused some regional waterways to rapidly rise. The Kankakee River rose to 15.62 feet on January 26—a historic crest for the river—due to an ice jam near Wilmington, Illinois which prompted evacuations in the area (Figure 7). By the end of the week, the Kankakee River levels were falling, but the Illinois River began rising by January 31. It was expected to cause minor flooding in low-lying areas of Peoria.