April and May are better if you can go then, but warm spells early on can trigger some good fishing activity, it's just a gamble and the wind can be a problem. The Tarpon migration really gets going May and June. I stayed at Grassy Key in mid May 2012 and there were Tarpon everywhere on the flats and around the bridges. I landed one around 70 lbs on a fly from a boat I rented at grassy key? It was a blast! I just got back from West Palm Beach where my daughter lives and Fished for bass in ponds around her neighborhood and caught plenty on flies. Spent one full day with Capt Mark Giacobba in Flamingo and landed a 60 lb tarpon on a fly. Plus we caught small bass and speckled trout. The snook didn't cooperate on this trip. The Everglades trip is a lot more remote and less crowded than the Keys, but I like the Keys too. If nothing much is biting you can still catch sharks, snapppers, or cudas. It seems backup plans are always available. Mark is a good guide and he is flexible on what's available at a given time. Just my 2 cents on my limited experience there. If you like sea food you must try the hogfish, they are awsome! The markets and restraunts have hogfish in the Keys. Conch fritters are a great appetizer with remoulade sauce. And of course Keylime pie.