Today’s high temperature is more than twenty degrees below the average for the Louisville area. The unusually cold air will stick around a little while longer.Forecaster Angie Lese with the National Weather Service in Louisville says the extremely cold temperatures are being caused by a mass of frigid air that moved in from Canada. It’s not moving quickly."Over the weekend, we should warm up to still chilly highs but much warmer than today and tomorrow, looking for highs in the upper 30s probably by Saturday and Sunday," says Lese.Along with the temperature shift, comes a small slight of snow.As temps remain below freezing, a number of area homeless shelters have raised a white flag, signaling all who seek shelter will find it there.