Current official forecasts from the Japan Meteorological Agency and ensemble models indicate a highest temperature of 25–26°C in Tokyo on September 5, driven by a lingering frontal boundary and northeasterly flow that sustains extensive cloud cover, scattered showers, and high humidity. These conditions limit daytime solar heating and promote evaporative cooling, keeping maxima below the late-summer climatological average near 29°C. Recent model runs show tight clustering around these values, with minor spread arising from uncertainties in exact cloud timing and precipitation intensity. Traders assign roughly equal weight to 25°C and 26°C outcomes, reflecting the narrow but genuine range still possible before the next forecast cycle.