Current temperatures are apparently causing 'exploding trees' in Chicago. Here’s what that actually means.

If your social feeds have recently warned you about “exploding trees” in Chicago—sometimes accompanied by AI-generated clips of trunks detonating like fireworks—take a breath. The sounds are real, but the explosions are not.

What people are actually hearing during bouts of extreme cold is a phenomenon known as a frost crack. It’s dramatic, loud and unsettling if you’ve never experienced it before, but it’s simply physics, not unexpected arboreal combustion.

When temperatures plunge rapidly, especially during sharp Arctic blasts, the outer layers of a tree cool and contract much faster than the inner core. At the same time, sap inside the tree begins to freeze and ultimately expand, like water. The result makes a tug-of-war of pressure, as the outside of the tree shrinks inward while the inside pushes outward. Eventually, something gives.

When the tension reaches a breaking point, the trunk can split vertically with a sudden loud crack. The noise is what’s fueling the “exploding tree” myth. But if you investigate afterward, you won’t find wood shrapnel or scorched bark, just a long, straight fissure running up the trunk.

Meteorologists across the Midwest have called out the viral framing as clickbait. While rapid temperature drops can cause cracking, trees don’t randomly blow apart simply because it’s cold. In fact, in winters like Chicago’s, where subfreezing conditions have already lingered for weeks, most sap has gradually frozen, reducing the likelihood of dramatic cracks. A sudden plunge after a mild stretch is when frost cracks are most likely to happen.

Frost cracks usually don’t kill trees. As temperatures rise, the wood often expands and the crack partially closes. Over time, trees will scar over and continue growing, though those vertical ridges you see on older trunks are usually the legacy of repeated frost cracking over multiple winters.

In the end, your neighborhood trees aren’t about to explode. They’re just reacting (loudly) to physics doing what physics does when winter turns brutally cold. If a post makes it sound cinematic, viral and terrifying, double-check the source—or stick with updates from credentialed meteorologists and agencies like the National Oceanic and Atmospheric Administration.

Chicago winters are harsh enough without adding imaginary tree bombs to the forecast.