As bobbiwoz said the pools are open year-round and they generally have similar activities year-round except special ones for holidays. My daughter has gone in the pool in December and January, but I don't usually go in until May. It can be pleasant to walk or ride bikes on the beach in March, and there are some nearby nature trails where birds can be seen etc. To sum up, there's a lot to do in March/early spring but I wouldn't count on full days at the beach or pool.