A few years ago, I did a very unscientific analysis of year-over-year bug reports on AA vs. ice out dates, and found that the window is about three weeks long.  I doubt that I still have my little excel sheet anywhere, but that was what I concluded. 

However, your mileage may vary, depending on the type of area you are in.  A boggy area is going to see more fun and games than say an elevated hardwood area.

MartinG wrote:

I think there is more to a sustained hatch of biting black flys than just ice out. i have found you are pretty safe before Victoria Day weekend. Regardless of ice out date.

 
Agreed. Go in on the Friday and you’re usually ok. By the time you’re leaving Monday you’re usually digging the bug spray out.