Ensemble forecasts from the National Weather Service and NOAA indicate Miami’s May 20 overnight low will likely settle near the seasonal average of 75–77 °F under persistent high pressure and light easterly flow. Typical subtropical moisture and a moderating sea breeze keep the diurnal range narrow, while scattered afternoon thunderstorms could briefly enhance radiative cooling after sunset. Historical records show lows dip to 73 °F or below roughly once every three years in late May, yet recent model runs also allow for drier boundary-layer air that could push the minimum above 80 °F on rare occasions. With market-implied odds split evenly between the coldest and warmest bins, traders are pricing this inherent variability in short-term thermodynamic profiles rather than any single anomalous signal. Updated NWS guidance expected within 48 hours will clarify whether steering currents or moisture anomalies shift the most probable outcome.