After a short reprieve, people across southern Manitoba are having to face frigid temperatures again starting tonight.

A wind chill warning is in effect Wednesday night for southwestern Manitoba, including Brandon and Carberry, meaning it will feel colder than –40 C.

In such frigid conditions, exposed skin can get frostbite in less than 10 minutes.

The Fort La Bosse school division in the Virden area has closed its schools and buses are not running due to the cold.

In the Park West School Division in the Birtle area, buses are cancelled but schools are open. Information on high school exams there will be posted on the division's website later this morning.

No wind chill warning has been issued for the Winnipeg area, but it's going to be cold there, too: the mercury is expected to dip to –24 C overnight, but with the wind chill it could feel as cold as –36 C, according to Environment Canada.

"Thursday will the coldest day of the week when you combine the temperature in the afternoon with the wind," CBC meteorologist John Sauder wrote in his weather journal on Wednesday afternoon.

"We'll have winds gusting 50 km/h in the morning and 40 km/h in the afternoon which, at –25 degrees, will create wind chills that put us in the '10 minutes or less' freeze time on exposed skin," he added.

The cold temperatures are being blamed on a blast of Arctic air that is pushing into southern Manitoba.

The good news: temperatures should return to normal by Sunday.