**Official forecasts from the Japan Meteorological Agency position 28–30°C as the most likely range for Tokyo’s August 11 high.** The latest three-day outlook, issued August 10, calls for a mostly cloudy day turning rainy later, with a maximum of 30°C and minimum of 22°C—slightly below the long-term August average of roughly 31°C. Persistent cloud cover and increasing precipitation reduce solar heating and limit afternoon warming, which has pulled trader consensus toward the lower end of typical summer values. Seasonal outlooks from the JMA indicate above-normal temperatures for summer 2026 overall due to a strengthened Pacific High, yet short-term model guidance for this specific date emphasizes the cooling influence of moisture and reduced insolation. Historical analogs for similar cloudy, rainy August days in Tokyo show highs frequently settling 1–3°C below clear-sky peaks. No significant typhoon or extreme heat signals appear in current guidance, keeping the distribution tightly centered on 28–30°C with lower odds on outliers above 31°C or below 27°C. Updated model runs and the next JMA briefing remain key near-term catalysts.