**Official National Weather Service forecasts for Miami on August 28, 2026, call for sunny conditions with a 30-40% chance of mainly morning showers or thunderstorms, yielding highs in the lower 90s (near 90–92°F).** This aligns closely with the long-term average high of ~90.4°F for the date and positions the 92–93°F bin as the clear market favorite at 66.5% implied probability, followed by 90–91°F at 29%. Key scientific drivers include typical late-August subtropical conditions: strong solar heating under mostly clear skies, light southeast winds, and high humidity that supports heat indices above 100°F but limits extreme surface warming through scattered convection and sea-breeze effects. Hourly model guidance shows temperatures peaking in the upper 80s to low 90s by afternoon, with any thunderstorms potentially capping further rises. The very low odds on 94°F+ or sub-90°F outcomes reflect the narrow forecast spread and absence of atypical steering patterns or moisture anomalies that could shift the range. Traders are effectively pricing the consensus NWS outlook and historical analogs, with resolution depending on the official daily maximum recorded at Miami International Airport.