**Trader sentiment clusters on 78-81°F outcomes for Miami's July 28 minimum because official guidance from the National Weather Service and AccuWeather points to overnight lows in that range under typical subtropical July conditions.** High humidity and frequent scattered thunderstorms limit radiative cooling, keeping temperatures from dropping much below the long-term normal minimum of 78°F at Miami International Airport. Forecast models show modest spread in cloud cover and wind overnight, which can shift the exact low by a degree or two and explains why adjacent bins like 74-75°F and 82-83°F retain meaningful implied probability. With resolution based on the official station reading, traders are pricing the balance between persistent warm, moist air masses and any brief clearing that could allow slightly greater cooling.