Official forecasts from the Japan Meteorological Agency show Tokyo’s overnight low reaching 22°C on August 11 under a persistent Pacific High, increased cloud cover, and rising humidity that limits radiational cooling. This places the reading slightly below the long-term August minimum of 23.7°C. Model consensus across official sources has converged on this threshold, with only minor 1°C variations possible from shifts in cloud timing or precipitation timing. Traders have priced in near-certainty because resolution hinges on verified station observations rather than forecasts, and current conditions leave little room for the low to deviate meaningfully. Clearer skies or drier air could theoretically allow an extra degree of cooling, though latest guidance shows no such development.