Wearing a jacket was a good idea Tuesday morning as chilly fall temperatures throughout the state helped frost cling to car windshields and plants.

The overnight low temperature at the Bismarck Airport was 27 degrees, according to Jon Chamberlain, a forecaster for the National Weather Service.

"That's a pretty good freeze," Chamberlain said.

Chamberlain said the airport would have the coldest reading in Bismarck because of its low elevation. He said at times the north end of town is 10 degrees higher than the airport.

County extension agents contacted Tuesday said some crops were damaged by the frost.

Kidder County Extension Agent Craig Kleven said corn will see some damage along with small grains that aren't fully matured.

Kleven said most of the calls from concerned ranchers were about hayland with sorghum and sudan grass.

Frost can cause high levels of prussic acid in sorghum and sudan grass. Kleven recommends keeping cattle from grazing those varieties for seven days after a frost. After sorghum and sudan grass are baled and have been given time to cure, they are safe for cattle, he said.

Tim Semler, the Bottineau County extension agent, said Tuesday's freeze lasted from 1:30 a.m. to sunrise.

Semler said most crops are mature enough that Tuesday's frost won't damage them. However, he is concerned that another frost could cause greater damage.

"There's supposed to be a harder frost in a couple of days. That's where we're concerned," Semler said.

Advice Semler gives to people growing garden vegetables is to either keep covering them or harvest them.

Chamberlain said Tuesday that some warmer air is expected to move into the area, but by the weekend temperatures will drop.

The forecast calls for lows in the mid-40s today, upper 30s on Thursday and upper 20s on Friday. The highs should be in the upper 60s Wednesday and Thursday. On Friday, the highs are expected to be in the mid-40s.