Recent National Weather Service guidance for Miami indicates an overnight low in the mid-to-upper 70s on May 20, driven by persistent southerly flow off the Atlantic and Gulf waters holding dew points near 72°F. This moisture limits radiational cooling under the subtropical high, keeping minimum temperatures aligned with climatological norms of 74–78°F for mid-May at Miami International Airport. Ensemble model spreads remain narrow, with minor differences in boundary-layer mixing and cloud cover determining whether readings settle near 76–77°F or edge into the 78–81°F range. No cold fronts or dry-air intrusions are forecast within the next 72 hours, so traders are weighing subtle variations in sea-surface temperature anomalies and wind speed that could shift the exact minimum by 2–3°F.