Latest Japan Meteorological Agency guidance and supporting models point to a Tokyo minimum near the 23.6°C seasonal normal on August 17, with cloudy skies and scattered showers expected to limit nocturnal radiative cooling while suppressing daytime heat buildup. This pattern keeps overnight readings tightly clustered around 23–24°C, explaining the market’s near-even split (41% for 23°C, 39.5% for 24°C). Key differentiating variables include the precise timing and coverage of cloud breaks, which could allow slightly greater cooling toward 22°C, versus any reduction in showers or lighter winds that might hold the low at or above 24°C. Urban heat-island effects in central Tokyo further anchor minima near these values, with only modest probability mass extending outside the 22–25°C band until final observational data resolve the outcome.