Des Moines, IA – From Des Moines to Cedar Rapids, Iowans could soon hear loud, startling booms echoing through the night as temperatures plunge below freezing. According to the Iowa Geological Survey, those explosive sounds are likely frost quakes — rare natural events caused by frozen ground cracking under sudden pressure.
Also known as cryoseisms, frost quakes occur when rain or melted snow seeps into the soil and freezes too quickly. As that water expands into ice, it builds immense pressure underground until it fractures with a sharp, thunder-like crack that can rattle windows or briefly shake nearby homes.
Meteorologists say Iowa’s weather pattern this week is primed for frost quakes: mild rain followed by an arctic blast dropping temperatures from the 30s into the single digits within hours. Areas with little or no snow cover — especially in central and eastern Iowa — are at higher risk, since snow normally insulates the ground from freezing so quickly.
These events usually occur between midnight and dawn, when the cold is most intense. While frost quakes are not dangerous, they can cause small cracks in driveways, foundations, or frost heaves in yards.
Experts recommend improving drainage and keeping water away from homes before the next freeze to minimize risk.
So if you’re awakened by a thunder-like boom on a calm, icy night from Des Moines to Cedar Rapids, it’s not construction or fireworks — it’s just Iowa’s frozen ground cracking beneath your feet.
