Recent ensemble forecasts from NOAA and the European Centre for Medium-Range Weather Forecasts show South Florida under a strengthening subtropical ridge, producing light southerly flow and ample May sunshine that supports daytime highs in the mid-to-upper 80s. The market’s close split between 86–87 °F and 88–89 °F stems from small but consequential differences in predicted boundary-layer moisture, sea-breeze timing, and afternoon cloud cover that can add or subtract 1–2 °F from the daily maximum. Historical mid-May climatology for Miami International Airport places the average high near 86 °F, giving traders a clear baseline against which current model consensus is being measured. The next round of 12–48-hour model runs and the NWS Miami forecast discussion are expected to narrow the range before May 18.