Remember if you are close enough to hear thunder you are in danger of being struck by lightning. Here is a fun (But be safe...while indoors of course!) way to estimate how far away a lightning strike is:
"Flash to Bang"
You can estimate the distance to a thunderstorm using the "Flash to Bang" (time from seeing lightning until your hear thunder) by counting the seconds between the lightning "flash" and the "bang" of thunder. Each five seconds equals one mile. If you count 15 seconds, the flash was 3 miles away and you know that you are in a high danger zone. Six miles is still in the high danger zone.