By Julie Weisenhorn
Excerpt from MN Weather Talk blog by Mark Seeley, U of M Climatologist
Frost Depths Increase: The spell of abnormally cold weather combined with the thin snow cover continues to allow frost depths to go deeper into the soil. In southern Minnesota counties frost depths now range from 25 to 35 inches, while in northern counties many frost depths are reported that are deeper than 40 and 50 inches. Shallow soil temperatures, 2-4 inches have fallen this week into the teens F and even the single digits F in some places. Such low temperatures present a threat of winter injury to alfalfa fields and other plants. Maximum frost depths usually occur near the end of February or early March, so the depth of frost in Minnesota has likely not reached its maximum extent for this winter. Read more.