Record low temps are possible for several Louisiana cities including Lafayette over the next 24 hours.
The National Weather Service says several daily records are likely to fall Tuesday as arctic air spends a second day in Louisiana.
Monday's low of 20 in Monroe was a degree below the previous Jan. 6 record set in 1959.
Weather service meteorologist Michael Berry says Shreveport's daily record could fall on Tuesday.
The weather service in Lake Charles says that could also happen in Lake Charles and Lafayette, where predicted lows of 17 degrees would tie or break records set in 1924, and in Alexandria, where a predicted low of 13 would be five degrees below the 1970 record for Jan. 7.
The weather service describes it as the coldest airmass to hit north Louisiana since February 1996.
Cold weather is also extending the holiday break for students in the East Baton Rouge Parish city of Central - but, so far, not for their teachers.
But an official-looking cold closure notice for Ouachita Parish schools was a fake, said Superintendent Bob Webber.
Webber said a prankster duplicated the school board website and posted that weather would close schools on Monday. Schools will be open Monday, he said.
Monday is the last day of vacation in East Baton Rouge Parish schools. But with wind chill expected as low as 10 degrees on Tuesday, Central Community Schools Superintendent Michael Faulk cancelled Tuesday's classes, saying he would decide Monday whether faculty and staff must return on Tuesday. The city has two elementary schools and an intermediate, a middle and a high school.
With lows expected from the teens in north Louisiana to freezing in the far southeast and winds that would make it feel even colder, many homeless shelters were admitting all comers on Sunday afternoon and planned to do so again Monday night. Clear skies at night would mean Monday morning temperatures in the upper teens and a wind chill in the single digits in north Louisiana, said National Weather Service meteorologist Aaron Stevens in Shreveport.
Farmers hustled to harvest citrus and protect strawberries, Terrebonne Parish jail inmates got extra blankets and people were warned to protect pipes, plants and pets as arctic air smacked into the state on Sunday.
New Orleans and Shreveport were among cities implementing freeze plans to ensure that nobody would be turned away from shelters for the homeless. The four privately run shelters in New Orleans all would be open without charge, a city news release said.
Inmates in the Terrebonne Parish Jail were getting extra blankets because one of the two boilers that heat the jail was broken, Sheriff Jerry Larpenter told The Courier on Saturday (http://bit.ly/JCEfTb ). He said temperatures Saturday were between 60 and 65 degrees. "There's no inhumane treatment," he said.
A supervisor who would identify herself only as Lt. Chamberlain told The Associated Press that questions about conditions in the jail on Sunday would have to be answered by the warden on Monday.
Larpenter said the Terrebonne Parish Council is expected to approve about $59,000 on Monday for two new heaters, which will be installed as soon as possible.
Pets and potted plants should be inside if possible, experts said.
With two freezing nights ahead, Louisiana citrus farmers - most of them in Plaquemines Parish south of New Orleans - were picking what they could of the last of their crop.
"We're scrambling right now," said Ben Becnel Jr. He estimated that Ben & Ben Becnel Inc. had about 5,000 bushels of fruit on the trees, mostly navel oranges and the sweet, thin-skinned mandarin oranges called satsumas.
Citrus is picked by hand, reaching up from the ground or out from short ladders to reach the tops of 10- to 12-foot trees and place the fruit in 5-gallon buckets. Becnel said he and his 10 workers should be able to get 1,000 bushels boxed before Tuesday.
Livingston Parish farmer Frank Fekete said he'd covered about one-fifth of his 50,000 strawberry plants - the earliest planted - with Agribond "blankets".
"They've got crowns down into the heart of the plant," he said. If those freeze, Fekete said, flowers will die before they emerge.
With 5 acres in strawberries and another 20 acres in crops such as cabbage, broccoli, beets and onions, he said, he can't cover everything.