The Parkland Region, on the Saskatchewan side, is under an extreme cold warning.
Yorkton, Melville, Churchbridge, Kipling, Wadena, Kelvington and Foam Lake are among several areas under the warning.
The forecast for tonight calls for a low of minus 28 with the wind chill value nearing minus 40, and temperatures down in the minus 23 to 27 region through to Friday.