Fact Check: Real Data Shows Climate Change Isn’t Worsening Illinois Storms

The Chicago Tribune recently ran a story claiming that climate change is making storms in Illinois “more severe,” particularly concerning hail and tornadoes. This is false. [some emphasis, links added]

There is no evidence that hail is becoming larger or tornadoes more powerful, or that either has become more common. The article relies entirely on computer model projections that are presented as fact, without reference to real-world data.

The Tribune article suggests that higher insurance claims are evidence that storms are more destructive, but this isn’t actually evidence of anything other than increased property values.

The article, titled “Gargantuan hail, destructive tornadoes: Climate change making Illinois storms more severe,” claims that as warming continues to raise average global temperatures,

“[H]ailstones larger than ping-pong or golf balls will become more frequent […] according to a study led by Gensini and published a couple of years ago in the scientific journal npj Climate and Atmospheric Science.”

The study is a few years old [August 2024], but it comes up almost every time the media wants to tie a notable hail event to climate change.

It is not based on real-world observations, but rather projections from computer modeling, which assume that global warming will result in more storms with stronger updrafts, which would allow for larger hailstorm formation before they drop to earth.

This same assumption was behind an NBC News report from July 2025 that was refuted in Climate Realism by meteorologist Anthony Watts.

In that post, Watts points out:

Hail formation requires a very specific cocktail of atmospheric conditions, including strong updrafts and a freezing layer deep enough to support hail growth. Warmer temperatures tend to reduce the vertical depth of this freezing level, making it more difficult—not easier—for large hailstones to form and survive to ground level.

He also points to studies that actually did look at measured severe hail occurrence, which found a decrease in significant hail events in the United States in recent decades.

Looking at National Weather Service data for Illinois alone, from 1995 to 2025, there is no trend towards more hail.

Computer model outputs are only as good as the assumptions and formulas built into them. In this case, the models are seriously flawed, as the long-term data demonstrates.

There is no trend towards worse or more frequent hail.

While the article title also implies that tornadoes are also worsening due to climate change, tornadoes are hardly mentioned in the body of the article.

That’s good for the Chicago Tribune, because the reality is that tornadoes are also NOT becoming more extreme or common in Illinois. It is shameful that they tried to imply that correlation.

Even though the story itself doesn’t get into it, it’s still worth presenting the data that debunks what is implied in the article’s title.

Looking at the overall tornado counts, there appears to be a slight upward trend; however, this is an artifact of the introduction of better radar systems that had wider coverage introduced throughout the mid-1990s, capturing smaller, briefer tornadoes in locations the earlier system missed.

The number of weak and short-lived tornadoes observed has increased greatly because they are now more easily spotted. Severe tornadoes, however, have not increased.

Most tornadoes happen in central and southeast Illinois, and most studies looking at Illinois storms focus there, but since this article talks about the Chicagoland area as well, Climate Realism presents data for all of Illinois.

Since 1995, using data from the National Weather Service’s Storm Prediction Center, grounded mostly in modern detection technology. (See figures 2 and 3 below)

Data show no consistent trend towards an increase in the number of tornadoes, powerful or otherwise, despite 2023-2025 being high-count years.

What should be among the most embarrassing parts of the article for the Chicago Tribune, aside from their lack of fact-checking data on hail and tornadoes, is when the paper tries to tie rising insurance claims from hail damage as proof that climate change is making hail worse.

What the Chicago Tribune fails to note, as covered by multiple Climate Realism posts on the subject of insurance (here, here, here, for example), is that this is a terrible metric for measuring weather severity.

That’s because while the weather has not become more extreme, property values have become higher, and inflation, affecting both labor and material, has resulted in dramatically more expensive replacement costs.

That means the cost of insurance claims rises, too. This is basic economic logic, reinforced by the weather data shared above.

The Chicago Tribune failed in its journalistic duty of producing a story grounded in facts. Instead of merely reporting on the danger and interesting human interest aspects of the recent severe storms, they attempted to fearmonger people into believing extreme weather is getting worse due to climate change.

It’s not, as historical observational weather data show that there is no sustained trend of worsening storms.

The computer model projections the Chicago Tribune cited as showing climate change-worsened weather are not much better than the simulations produced by fantasy computer games.

Read more at Climate Realism