Southern Ontario once again finds itself under an extreme cold warning.

Environment Canada issued the alert Thursday morning, in advance of what’s expected to be another chilly night.

In this part of the province, an extreme cold warning is issued whenever temperatures or wind chill values are expected to hit -30.

Overnight, forecasters are calling for a low of -25 C and wind chill value of -33 in Waterloo Region and southern Wellington County, with northern parts of the county one degree colder.

In Oxford-Brant, temperatures are expected to fall to -24 C, with a wind chill of -30, while the figures for Huron-Perth and Grey-Bruce stand at -26 C and -34.

Forecasts for Friday call for clear skies with daytime highs of -14 C in Bruce-Grey and Waterloo-Wellington, -13 C in Huron-Perth and -12 C in Oxford-Brant.