Current National Weather Service and AccuWeather guidance points to overnight lows near 80–82 °F in Miami on August 21, consistent with the closely matched market-implied probabilities for the 80–81 °F and 82–83 °F bins. Typical late-summer conditions—high humidity, light winds, and scattered convective activity—limit radiational cooling, while any increase in cloud cover or thunderstorm outflow could nudge the minimum a degree or two lower. Model consensus shows minimal day-to-day variability this week, with sea-breeze influences and residual moisture from the Atlantic keeping temperatures anchored near seasonal normals of roughly 78–80 °F. Updated short-range forecasts and evening observations will provide the final data for resolution.