Hail Storms

The National Severe Storms Laboratory (NOAA) stated that “We really only have estimates about the speed hail falls. One estimate is that a 1cm hailstone falls at 9 m/s, and an 8cm stone, weighing .7kg falls at 48 m/s (171 km/h).”

(http://www.nssl.noaa.gov/primer/hail/hail_basics.html)

To give you a idea in MPH:

A hail stone of 1 centimetre (0.39 in) in diameter falls at a rate of 9 metres per second (20 mph), while stones the size of 8 centimetres (3.1 in) in diameter fall at a rate of 48 metres per second (110 mph).

Here are 2 videos that give you an example of how quickly a hail storm can create damage:

Both of these videos were shot in May, 2010