The weather service states, "Dangerously cold wind chills as low as 30 to 35 degrees below expected." Understanding cold weather alertsExtreme cold warning: Take Action! An extreme cold warning is issued when dangerously cold air temperatures or wind chill values are expected or occurring. An extreme cold watch is issued when dangerously cold air temperatures or wind chill values are possible. A cold weather advisory is issued when seasonably cold air temperatures or wind chill values, but not extremely cold values, are expected or occurring.