May 01 | Climate Review and Weather Update
by Trent Ford, State Climatologist
ISWS PRI University of Illinois
Well, the last week of April was much like the month as a whole. Average temperature ranged from the mid-50s in northern Illinois to high 60s in southern Illinois, between 5 and 10 degrees above average. The month as a whole ended between 4 and 8 degrees above average, likely making April a top 5 warmest on record statewide. With that said, clear skies on a few nights allowed early morning temperatures to regularly dip into the 30s this week, including lows of 31 in Waukegan and 34 in Normal.
We also had yet another active severe weather week, with several tornadoes, hail events, and widespread strong winds. Folks in Champaign-Urbana were greeted with tornado warnings on Monday morning and Monday night, with significant tornado and wind damage in parts of Macon, DeWitt, Piatt, and Champaign Counties this week. The official state tornado count isn’t updated with this week’s events; however, Illinois has already had well over 100 tornadoes. For perspective, the state has averaged around 60 tornadoes per year over the past 60 years. Unsurprisingly, Illinois leads the nation in tornado reports this year with 119. The next closest state is Mississippi with 53, so yeah, it’s been a minute.
The storms brought significant rainfall across the state again. 7-day totals ranged from around a half an inch in far northern Illinois to over 4 inches in south-central Illinois. April was 1 to 8 inches wetter than average in most places north of Interstate 70, and 1 to 4 inches drier than average in far southern Illinois. Last month was likely a top 10 wettest April on record statewide, and the wettest since 2013.
Looking ahead, the first week of May will actually be a bit milder, if not cooler. High temperatures will struggle to make it out of the 60s statewide next week, with nighttime lows in the 30s and 40s. The 7-day rainfall forecast would give us what we need, with mostly less than a quarter of an inch in water-logged northern Illinois, and around an inch to 1.5 inches in southern Illinois, where rain is needed to really jumpstart beans and pasture.