Temperatures have dropped significantly in Edmonton this week, but it is only a taste of how cold it's expected to get.

On Thursday, the city activated its cold weather protocol and opened the Commonwealth Community Recreation Centre to shelter the homeless overnight. Forty-five people spent the night in the rec centre, and the city said the majority of shelter space throughout the city had been filled. 

"With daytime highs Friday and Saturday of -16 C to -18 C, Sunday will mark the arrival of a colder and clearer Arctic air mass," CTV News Edmonton meteorologist Cory Edel said. "On Sunday, daytime highs will hover between -23 C and -27 C and into next week. Overnight lows will also drop to and below -30 C, with wind chill values approaching -35 C to -40 C."

Edel expects Environment Canada to put an extreme cold weather warning in place for Edmonton and its surrouding area in the coming days. The warning is already in effect in the Fort Saskatchewan and Wood Buffalo areas.

The agency is reminding Albertans to cover up as frostbite can develop quickly and not to leave pets outside for long periods of time.

The City of Edmonton and City of St. Albert urge the public to call 911 if they see someone in distress due to the cold.

Warning signs may include uncontrollable shivering, fumbling hands, drowsiness, confusion and slurred speech, the City of Edmonton said.

For more information about the City of Edmonton's extreme weather protocol, click here.