Recent official forecasts from the Japan Meteorological Agency and ensemble models point to a stationary front delivering persistent cloud cover, scattered showers, and reduced solar insolation over Tokyo on August 29, suppressing maximum temperatures below seasonal norms of ~31 °C. Highs are projected near 27–29 °C with elevated humidity and light northeasterly flow, consistent with the market’s heaviest weighting on 27 °C (38.5 %) and 28 °C (28.5 %). Minor model spread around precipitation timing and intensity creates the observed dispersion toward 26 °C, while the low odds on 29 °C or higher reflect limited potential for brief clearing that would allow stronger afternoon heating. Updated guidance expected overnight will refine these probabilities ahead of market resolution.