February 5, 2003
The State Climatology Office has issued the following statement concerning soil frost depths:
“…soil frost depths increased rapidly across Minnesota during January. Cold temperatures, combined with limited snow cover, caused soil frost to penetrate beyond 24 inches in depth beneath sod-covered surfaces, and deeper under bare soil. For many locations, soil frost is at the deepest levels observed in more than a decade. Soil frost historically reaches maximum depth in late February.”
Here’s a map of the North Central area frost depths.