The weather alert applies to High Level and Fort Chipewyan in the north down to Medicine Hat and Brooks in the south.
Areas surrounding Edmonton are also under alert: Leduc, Camrose, Wetaskiwin and Tofield to the southeast, Fort Saskatchewan, Vegreville to the east and Westlock and Barrhead to the north.
The coldest wind chill values will be near –40 C, Environment Canada says on its website.
The weather agency attributes the extreme cold snap to an Arctic air mass moving into Alberta.
The wind chill is expected to rise Monday afternoon to –20 C.
Relief from the extreme cold is expected by Wednesday afternoon.
Environment Canada reminds people that frostbite can develop within minutes on exposed skin, especially with wind chill.
“If it’s too cold for you to stay outside, it’s too cold for your pet to stay outside.”
Edmonton was under an extreme cold warning for 14 straight days at the beginning of February.