(AP) — Subzero cold and chilling winds have forced many Iowa and Nebraska schools to cancel classes or delay opening by a couple of hours.

The National Weather Service says temperatures across Iowa on Thursday morning were as low as minus 12 in Mason City, with a wind chill of minus 37. In Davenport the wind chill was minus 29. In Sioux City the wind chill was minus 26 around 6 a.m. A wind chill of minus 25 was reported for Des Moines.

Valentine in north-central Nebraska was reporting minus 8 at 6 a.m. Omaha was reporting minus 5, with a wind chill of minus 24.

In the far western Nebraska Panhandle, Scottsbluff was reporting a temperature of 10, with a wind chill of minus 1.