Here's how cold it was across Alberta during that brutal week and a half in January

More than 30 per cent of the weather stations scattered across Alberta recorded temperatures below –40 C during the brutal cold snap that struck the province earlier this month.

The deep freeze was the result of Arctic air that began flowing into the province from the north on Jan. 5, according to Ralph Wright, who leads the agrometeorology applications and modelling unit at Alberta Agriculture and Forestry.

By Jan. 12, "the entire province was under the influence of an Arctic air mass," he said in a provincial synopsis of the cold snap, which persisted for more than a week.

In southern Alberta, the lowest recorded temperatures were between –35 C and –30 C, while most of the province north of Calgary experienced temperatures of –38 C or lower.

Several areas between Red Deer and High Level saw lows of –43 C or colder.

The lowest temperature during the cold spell was –49.7 C, recorded on Jan. 15 about 30 kilometres north of Grande Cache.

A weather station just north of Edmonton, meanwhile, measured temperatures below –40 C for 39 hours during a two-day period.

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"Finally, by Jan. 20, the cold spell was over," Wright said.

"By Jan. 21, the change was dramatic, with many areas ranging from the town of Peace River all the way down to the U.S. border reporting daytime highs above the freezing mark."

The lowest temperature ever recorded in Alberta, according to the provincial synopsis, came more than a century ago: on Feb. 3, 1911, the temperature in Fort Vermilion dipped to –61.1 C.