Current JMA forecasts for Tokyo on August 22 indicate a minimum of 24–25°C under cloudy skies with scattered showers later, aligning with the market's tight clustering around 25°C (45%) and 26°C (41.5%). Persistent cloud cover and humidity limit nocturnal radiative cooling compared to clear nights, while showers and the urban heat island effect further moderate temperature drops below the seasonal normal low of 23.1°C. Model consensus favors these conditions over clearer scenarios that could allow 24°C or lower, though slight forecast revisions in maximum cooling potential or precipitation timing keep 24°C at 9.5% and 27°C at 6%. Updated model runs and official briefings in the next 48 hours represent key decision points for traders.