From ClimateRealism

By Linnea Lueken

The Chicago Tribune recently ran a story claiming that climate change is making storms in Illinois “more severe,” particularly with regard to hail and tornadoes. This is false. 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 it presents as fact, without reference to real world data. The 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, “hailstones 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, 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 on projections from computer modelling that assumes 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, which 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 demonstrate. 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 not becoming more extreme or common in Illinois. It is shameful to imply that correlation. Even though the story itself doesn’t get into it, it’s still worth presenting the data that debunk 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 tornados in locations the earlier system missed. The number of weak and short-lived tornados observed has increased greatly because they are now more easily spotted. Severe tornadoes, however, have not increased.

Most tornados occur 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, here are the data from the National Weather Service’s Storm Prediction Center, grounded mostly in the 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 than their lack of fact-checking data on hail and tornadoes, is when 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 weather has not become more extreme, property values have become higher and inflation, affecting both labor and materials, 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 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.