Traders are concentrating on the 78–81°F bins because official National Weather Service and private-model guidance for Miami on August 25 point to an overnight minimum near 80–82°F amid a moist tropical air mass, light southeast winds, and partial cloud cover that limits radiational cooling. Persistent high dew points near 76–78°F and heat indices above 100°F during the day have kept the boundary layer warm, while scattered showers and thunderstorms expected overnight add further insulation. Historical August minima average 77–78°F, yet the current pattern lacks any frontal passage or drier air that would allow deeper cooling, leaving only modest uncertainty from model differences in cloud timing and wind speed that separate the tightly grouped 78–79°F and 80–81°F outcomes.