Why is it dangerous to swim during a storm?

If lightning strikes and u r in water, then u could possibly get electrocuted.

The main reason is that during a storm there is often rain and heavy winds, the rain would generally be colder and could lower your core body temperature if you stayed out in it too long, it would also render it harder to see if it was heavy. The main concern though is the wind as you would have to fight against waves which could include whitecaps and the current of the water. It would tire you out very fast and there is a strong risk that you could drown.