Official observations from the Japan Meteorological Agency confirm a daily maximum of 22°C in Tokyo on September 10, 2026, under persistent rain and northeasterly flow that suppressed daytime heating. This aligns with the market’s near-certain 22°C outcome, reflecting verified station data rather than model projections. Cooler-than-normal conditions, with an average of 19.9°C and a minimum of 17.7°C, resulted from an incoming air mass and widespread precipitation that limited solar warming. Scenarios that could challenge the consensus remain limited at this stage, primarily involving post-hoc data revisions or alternative station readings, though historical September maxima average near 27°C and recent days reached 31–32°C before the current pattern shifted.