The Florida Keys see 400 to 500 waterspouts a year. Waterspouts moving ashore are a rare occurrence, however. Water spouts and funnel clouds are most frequently observed in the middle and lower Keys during the late spring and summer months. They tend to occur most often north of the islands, more so than directly over or south of the Keys. Contrary to popular belief, funnel clouds and waterspouts are not always associated with thunderstorms.
Waterspouts are most likely to form when the clouds are growing.
In the Keys, waterspouts have been observed forming from 7 a. m. through sunset but they most often form between 4 p.m. and 7 p.m., as with the June 18 tornado, with a secondary maximum from 11 a.m. to 1 p.m. Watch-standers must always keep a vigilant eye on any cloud development because of the explosive nature of connective activity in the lower Keys.