Late November 2008 we had a hailstorm that lasted about 10-15 minutes. Luckily the stones were only about 10mm in diameter but it took two days to melt away. These storms we have about twice a year but rarely with very big stones.
Here's some of the photos we took.
In '98 when i lived in Europe we had a hail storm. It lasted about 10 min, but 15 min later it came back and lasted another 10 min. There was about 8 inches of ice on the grund when it stopped hailing for good. I have never seen something like that before, or after that day. Luckily, it all melted the same day since the temp was in upper 90s, lower 100s.