Forecast models from the National Weather Service and others indicate Miami highs on September 23 will likely fall in the mid-to-upper 80s amid a classic late-summer pattern of abundant tropical moisture, high humidity, and afternoon convection. South to southwest flow and sea-breeze interactions favor scattered to numerous thunderstorms, with 70–90% rain probabilities that can cap temperatures through evaporative cooling and increased cloud cover once storms initiate. The tight clustering of market-implied odds around 84–89°F reflects model uncertainty in the precise timing and coverage of this convection: earlier or more widespread storms favor the lower bins while delayed or localized activity supports the higher ones. Updated model runs and National Hurricane Center outlooks through the next 48 hours will provide the clearest signals for any shifts.