Trent Ford, Illinois State Climatologist, provided this article.
April has continued our very warm and active spring, with average temperatures that have been 5 to 10 degrees warmer than average statewide (Figure 1). The warmth has pushed soil temperatures into the 60s and 70s statewide, well ahead of average for this time of the year.
The warmth has also come with very active severe weather statewide, and exceptionally wet conditions in northern Illinois (Figure 2). Most of the northern half of the state has been 2 to 10 inches wetter than average since late March. The spring season through April 27th has been the second wettest on record in Chicago with 10.63 inches of precipitation since March 1st. An active storm track has also brought several rounds of severe weather, including over 100 tornadoes since the start of the year in Illinois. 2026 will be the third consecutive year with 100+ tornadoes in the state, while only achieving that mark once before 2024. Meanwhile, much of southern Illinois has been left dry this spring and has been 2 to 4 inches drier than normal since late March.
Outlooks from the Climate Prediction Center show very few strong signals on temperature or precipitation in May and climatological summer. The most recent outlooks show equal chances of warmer, cooler, drier, and wetter than normal conditions for May and the period between May and July.
