Charlotte, NC – As arctic air moves in, residents from Charlotte to Raleigh may soon be awakened by mysterious booms echoing through the night — but it’s not thunder or blasting. According to the North Carolina Geological Survey, these startling winter sounds are likely frost quakes — sudden cracking events in the frozen ground caused by sharp drops in temperature.
Known scientifically as cryoseisms, frost quakes form when rain or melting snow seeps into the ground, then freezes too quickly. As the trapped moisture expands into ice, it builds pressure underground until the frozen soil suddenly splits apart, releasing energy with a thunder-like crack or rumble.
Meteorologists say conditions are lining up for possible frost quakes across the Piedmont and Foothills regions, especially after a stretch of mild, wet weather followed by plunging overnight temperatures. When the ground is saturated and there’s little snow cover to insulate it, the risk for frost quakes increases sharply.
These events typically strike between midnight and dawn, when temperatures are coldest. While frost quakes are short-lived and rarely damaging, they can startle residents and cause small cracks in driveways, patios, or foundations near the surface.
Experts recommend improving drainage around homes and ensuring water is directed away from structures before major freezes hit.
So if you’re startled by a loud boom on a calm, icy night from Charlotte to Raleigh, don’t panic — it’s just the frozen North Carolina ground cracking under winter’s pressure.
