The days of the cold air are dwindling. The lengthening days of the Arctic summer are going to put a crimp very quickly on the remaining cold. Still easily possible to get frost through May up here in midwest..but hopefully that doesn't occur.
Some significant shrinkage of our cold pool to the north between now and 10 days from now.
What you do start to worry about this time of the year is the 'cut off low'... a low pressure system that gets cut off from the flow so just sits and spins for days and days...ugly ugly ugly weather condition. Every so often that'll happen and its miserable. The low will jog a little..and many times move back west (normal flow is west to east)...days and days of clouds, rainy, showery conditions..cool...temps not moving much between day/night.