South Florida wind patterns are determined by the interaction of prevailing easterly tradewinds and localized land-sea convection patterns during the wet season, or cold fronts during the dry season. However, the daily wind regime typical of mainland coastal areas that result from differences in the heating rate of land and sea are not the normal pattern in the Keys. There simply is not enough land mass in the Keys to support the daily cyclic convection patterns that result in seabreezes during the day and landbreezes at night. For the most part, the winds experienced in the Keys are the result of pressure gradients associated with regional highs and lows.

The prevalence of easterly tradewinds are powerful in the Keys. Winds vary from due east in fall and winter to east-southeast in spring and summer. Seasonally, the highest average wind speeds are observed in late winter and early spring, and the lowest during the summer. On a typical day, wind speeds are lowest in the nighttime, increase during the day to a peak in the afternoon, and then decrease again in the evening. Locally, high winds may accompany summer thundershowers. Cold fronts moving across the state also influence the wind regime of the Keys as evidenced by the northerly component of the prevailing wind directions for the months of October through January.