Make sure the vent has a flapper at the end that shuts when not in use. Other than that, I don't know what can be done. Our dryer gets very cold too when not in use.

Thanks, I've checked that..maybe I'll put something a few feet away from the vent to block the wind....

You could put some sort of screen enclosure around your outlet. This will block wind and cold somewhat yet still allow moisture and air to escape. It is amazing what an insulating effect screen has. Our north screen porch does an excellent job of keeping cold out.

I have seen an attachment that fits on the hose behind the dryer. It has a flap in it so when the dryer stops it closes to stop the wind from getting past there. Don't know how well this works but 2 flappers might be better than one. Sometimes the ones outside doesn't close all the way or the wind might make them blow open also.

May have these at Lowe's, Home Depot or Ace Hardware.

I noticed a cold draft when I replaced our dryer as well - my repairman friend who helped install it said that's probably because my old dryer was so packed with lint the air couldn't get in....

Thanks to you all..I love the solution of the lint!11 will begin to look at all of suggestions.