**Trader sentiment for Miami's June 21 low temperature reflects typical late-June subtropical conditions, with leading bins clustered tightly around 76–81°F.** Official forecasts from sources such as the National Weather Service, AccuWeather, and timeanddate.com currently point to an overnight low near 79–81°F under partly cloudy skies, aligning with the market's top outcomes (78–79°F at 29%, followed closely by 76–77°F, 80–81°F, and others near 21%). Key scientific drivers include persistently high dew points (typically 73–77°F in Miami during this period), which limit nocturnal radiative cooling, combined with warm surrounding waters of the Gulf Stream and Florida Straits that maintain elevated boundary-layer temperatures. Light southeasterly winds and scattered convective activity—common in the afternoon/evening—can either enhance mixing (keeping lows higher) or allow brief clearer periods for slightly greater cooling. Model uncertainty in overnight cloud cover and any late-day showers creates the narrow spread across the 76–81°F range, while extremes below 74°F or above 84°F remain low-probability given the absence of atypical cold-air intrusions or extreme suppression this time of year. Updated model runs and National Weather Service briefings on June 20–21 will likely refine the exact minimum as the 24-hour window approaches.