Current forecast models from the Japan Meteorological Agency and international agencies converge on a Tokyo maximum of 28–29°C for August 13, tempered by widespread cloud cover and scattered showers or thunderstorms that limit afternoon heating. Precipitation probabilities of 50–90% during peak daylight hours represent the dominant variable suppressing temperatures below typical mid-August climatology of 31–32°C, while urban heat island effects and variable humidity could still push readings into the upper range. Lower outcomes (27°C or below) gain support from stronger rain timing, whereas 30°C or higher would require clearer skies and reduced moisture than current guidance indicates. Updated model runs and JMA briefings over the next 24 hours will likely refine these probabilities ahead of market resolution.