Hailstones seem to be getting bigger as severe storms become more frequent around Chicago and the rest of the Midwest, and scientists believe climate change is the biggest driving factor.
It’s been a very active spring for severe storms this year.
The state of Illinois has had over 110 tornadoes already and 174 severe hail reports (1 inch or greater). One of those reports was a state-record-breaking 6.14-inch hailstone from Kankakee on March 10.
The previous state record was 4.75 inches in Minooka from June 10, 2015.
These are the number of reports of 2-inch sized hail or greater in the past five years:
- 2026 (so far): 27
- 2025: 40
- 2024: 19
- 2023: 56
- 2022: 7
In the last 10 years, Illinois has averaged around 20 hail reports of 2 inches or greater per year. Forty years ago, that number was around six.
How is climate change contributing to larger hailstones?
As our climate continues to get warmer, so does the amount of moisture in the air. Warmer air with more moisture near the surface equates to stronger updrafts in thunderstorms.
Stronger updrafts can support larger hail stones as they cycle vertically through the upper-end of a thunderstorm.
Hail stones continue to grow until the updraft can no longer support it, and it falls to the ground.
Another important variable with a warming climate is a thicker melting layer in the cloud; meaning the freezing point is higher up in the cloud than previous climate averages.
A thicker melting layer gives more time for a hailstone to melt as it falls from the cloud. This 2024 study by Northern Illinois University shows a decline in small hail events, and a significant increase is larger hailstones.
This means we may continue to see an uptick in large damaging hail events, accompanied by more general severe weather events.
