Sioux City, Iowa – Residents along the Nebraska–Dakota border should be prepared for sudden loud cracks or booming sounds Friday as persistent Arctic cold renews the risk of the “exploding tree” phenomenon across the region.
According to the National Weather Service, deeply cold air remains locked in Friday, with subzero temperatures and biting wind chills creating ideal conditions for frost cracking, also known as cryoseismic booming. This occurs when sap inside trees freezes rapidly and expands while the outer wood contracts, building intense pressure that can cause trunks to split suddenly with a sharp, explosive sound.
The highest risk Friday morning spans northern Nebraska and southern South Dakota, including areas near Sioux City, South Sioux City, Yankton, Vermillion, Norfolk, and rural communities along Interstate 29 and Highway 81. River valleys, shelterbelts, and older neighborhoods with mature hardwood trees are especially vulnerable, with cracking most likely during the coldest pre-dawn hours.
While exploding trees are uncommon, splitting trunks and falling limbs can damage vehicles, sidewalks, roofs, and power lines. Residents are urged to avoid standing beneath large trees during extreme cold and to park vehicles away from tree-lined streets when possible.
The same cold driving tree stress also increases the risk of frostbite on exposed skin within minutes, frozen pipes, and vehicle problems. Officials advise limiting outdoor exposure Friday, wearing insulated layers, covering all exposed skin, and keeping pets indoors. Cold-related advisories remain in effect, and additional updates are possible if conditions persist or intensify.
