Summary (tl;dr)

As extreme cold grips parts of the United States, particularly the Midwest and Northern Plains, meteorologists are warning residents about the rare but real phenomenon of "exploding trees," where freezing sap causes tree trunks to crack loudly.

Essential Background

The phenomenon of "exploding trees," also known as frost cracking or cryoseismic booming, is not new, with historical accounts dating back to the 17th century and knowledge among Indigenous peoples like the Sioux and Cree. It occurs when temperatures drop drastically, causing the water within a tree's sap to freeze and expand. This expansion exerts immense pressure on the tree's internal structure and bark.

The Full Story

A significant winter storm and polar vortex are currently bringing dangerously low temperatures, forecasted to drop to -20 degrees Fahrenheit or lower, to large parts of the Midwest and Northern Plains of the United States. This severe cold snap has prompted meteorologists and weather enthusiasts, including popular social media meteorologist Max Velocity, to issue warnings about the increased risk of "exploding trees" this weekend. While not literal explosions, the rapid freezing and expansion of sap can cause the tree bark to split with a loud, gunshot-like sound. Trees with higher moisture content, such as oak, maple, and fruit trees, are particularly vulnerable to this phenomenon.

Why It Matters

While often more startling than dangerous, "exploding trees" can pose risks. The sudden cracking can cause heavy limbs or branches to fall, potentially damaging homes, vehicles, or power lines. The loud, unexpected noises can also be alarming for residents, with some comparing the sound to gunshots or bombs. Awareness of this phenomenon helps residents understand the unusual sounds they might hear during extreme cold and take precautions, such as avoiding wooded areas during peak cold periods.

Geographic Location

• Midwest and Northern Plains, United States (widespread warnings for exploding trees due to extreme cold)
• North Dakota, United States (risk of exploding trees)
• South Dakota, United States (risk of exploding trees)
• Minnesota, United States (risk of exploding trees)
• Wisconsin, United States (risk of exploding trees)
• Iowa, United States (risk of exploding trees)
• Michigan, United States (risk of exploding trees, particularly western portion)
• Princeton, Collin County, Texas, United States (experienced exploding trees during a 2022 cold front)