I've been to DC twice now. Both times in Sept. and both times we had to get off the beaches and out of the water due to an incoming storm. In 2007 the storm really never materialized and since many guests left the park, it was amazing! I had the Coral Reef mostly to myself.
Flash forward to last Sept. OMG! We've been to WDW about 10 or more times in Sept. and we witnessed the largest storm we ever have while at DC.

We were just finishing up our Dolphin swim (2 p.m.) and grabbed some desserts to enjoy on the beach. The 2:30 group had to leave due to the incoming storm. Then they asked us to leave the beaches so we sat under the coverings at the Laguna Grill. I decided to go get our free picture while it wasn't too busy. THEN THE SKIES OPENED UP AND THE LIGHTENING WAS INTENSE! You know, when you can hear the lightening make that sizzling kind of noise that tells you it's directly overhead? Problem was that they made everyone stay where we were until they gave the all clear. I have never witnessed so much rain in Floride before.

There were several moms who were with me in the photo pick up area and we were all anxious to make it back to our families. We had no way to contact them. It was so frustrating since we were basically separated from them by a block wall. We were holed up for about 45 mins. or so.
Then we (2 other moms and I) made a break for it and went to the Grill. Found my DM and DD11 inside the restaurant with a lot of other guests. The were packed in like sardines.

My DM said at first they told all guest to get under the roof coverings. Then they told all to move either into the bathrooms or into the restaurant. She chose the restaurant-the bathroom was pretty cold. We stood around in there for about another 15-20 minutes. (And yes I did get a little emotional after finding them-I knew my DD would be worried about me

Total time lost a little over an hour. At this point most of the guests left but I knew better! We hung around to see if they re-opened the beaches. They did! For about 10 more minutes. It was sprinkling while we were in the Coral Reef. Then the closed them again. By the time we left DC it was 5:45 p.m.
Most of the guests did their Dolphin swims but some elected to reschedule theirs for another day.
Here some pictures of the rain.
The rain started while we were finishing our Dolphin Swim
After the major rain was over-Coral Reef
DD11 and giant ray in the rain
This is during the main part of the deluge.
So is this one
So worth it!