Pinellas County is a peninsula on the west coast of Florida that receives sea breeze driven convective rainfall during the summer months. To improve forecasting of local mesoscale phenomena, the spatial variability of summer rainfall in Pinellas was examined in relation to dominant wind directions and speeds, atmospheric stability, and atmospheric moisture content for the months of June, July, and August from 2003 to 2007. Radiosonde data from the Ruskin, Florida National Weather Service (NWS) Station, Pinellas County rain gauge data, and radar-estimated rainfall totals from the NWS Advanced Hydrologic Prediction Service were used to examine different meteorological parameters and their relationships with the spatial variability of summer precipitation across the peninsula. Dominant daily wind direction categories were divided into six 60 degree increments: 1–60°, 61–120°, 121–160°, 161–240°, 241–300°, and 301–360°. Precipitable water had a significant positive correlation with precipitation in four of the six wind direction categories (61–120°, 121–180°, 181–240°, and 241–300°). Higher wind speeds associated with a southerly wind direction revealed significant positive relationships with precipitation. Composites of radar-derived rainfall estimates indicate that rain fell primarily in the center of the peninsula under a variety of wind directions, often with two daily maxima. Composites also show that the greatest potential for high precipitation amounts comes with westerly winds (241–300°).