Persistent rain and northerly flow across the Kanto region have capped Tokyo’s maximum temperature at 23°C on September 29, 2026, according to Japan Meteorological Agency observations and multiple model runs. Cloud cover, high humidity near 90 percent, and steady precipitation suppressed daytime heating, keeping hourly readings between 19–23 °C through the afternoon. Market-implied odds reflect this near-certainty, as late-day data releases are unlikely to alter the official high. Only an unanticipated late clearing or measurement revision at a key station could push the recorded maximum to 24 °C or higher, an outcome traders currently assign negligible probability.