February brought cold and first substantial snowfall to winter in Illinois

February brought the first snowstorms of the winter, with colder temperatures and higher precipitation than normal in Illinois, according to Illinois State Climatologist Trent Ford at the University of Illinois’ Illinois State Water Survey.

The preliminary statewide average February temperature was 27.2 degrees, 3 degrees below the 1991–2020 average.

February average temperatures ranged from the low 20s in northern and north-central Illinois to the high 30s in far southern Illinois, between 1 and 6 degrees below the 1991–2020 normal. Several stations saw daily high temperatures in the high 60s in mid-February, including 67 degrees in Alexander and Pope counties. Meanwhile, stations in northern and central Illinois saw nighttime low temperatures well below 0, including -9 degrees in Knox County and -8 degrees in Woodford County.

Precipitation

Total February precipitation ranged from less than 1 inch in far northwest Illinois to over 9 inches in parts of southern Illinois. Last month was about 1 inch drier than normal in northwest Illinois, 1 to 2 inches wetter than normal in central Illinois, and 4 to 7 inches wetter than normal in southern Illinois.

The preliminary statewide average total February precipitation was 3.41 inches, 1.48 inches above the 1991–2020 average.

The heavy February rain and snow melt in southern Illinois has caused several spots along the Wabash and Ohio rivers and tributaries to reach or exceed moderate flood stage. Excessively wet soils in southern Illinois also raise concerns of continued flooding risks and possible fieldwork issues as we approach the start of the growing season. Concurrently, the dry winter has not helped alleviate drought conditions across northern Illinois.

After a very slow start to winter, much of the state finally saw considerable snowfall in February. A series of winter storms in early to mid-February brought several rounds of moderate to heavy snowfall, with the highest totals along and around the Interstate 55 corridor from St. Louis to Chicago.

Overall, February total snowfall ranged from less than 4 inches in southern and far northwest Illinois to over 20 inches in parts of central and northeast Illinois.

Heavy February snowfall broke daily snowfall records at 53 stations in Illinois, and the 8.33 inches observed on Feb. 3 in Jerseyville broke their all-time February daily snowfall record. Some of the most impressive single-day snowfall totals from last month include 14 inches in Woodford County on Feb. 2, 11.8 inches in Cook County on Feb. 2, and 10.5 inches in Vermilion County on Feb. 3.

Outlooks

The most recent March outlooks from the Climate Prediction Center are leaning toward a warmer than normal start to spring and show strongly elevated odds of a wetter than normal March.

This is good news for parts of northern Illinois that have not had enough precipitation in winter to make up for drought and deficits in summer and fall. However, the news of a potentially wetter than normal start to spring is less welcome in southern Illinois. A wet start to an already typically wet season increases the risk of excessively wet soil issues and flooding in southern Illinois this spring.

The spring seasonal outlooks (March–May) are very similar to those for March, leaning toward warmer and wetter weather for most of the state.