Trader consensus has locked in a 100% implied probability on 15°C as Tokyo's lowest temperature on May 6, driven by Japan Meteorological Agency (JMA) nowcasts and real-time observations from official stations like Haneda, where morning readings started near 18°C under persistent cloud cover that limits radiative cooling overnight. Current evening temperatures hover around 17–18°C with mostly cloudy skies and light winds, aligning with model ensembles projecting a minimum in the mid-teens Celsius—consistent with May climatological norms of 13.6°C daily lows but elevated by recent frontal passages stabilizing the boundary layer. Realistic challenges include unexpected sky clearing after midnight, potentially dropping 1–2°C via enhanced infrared loss, though high humidity and urban heat island effects in Tokyo make sub-14°C unlikely; final JMA data release post-midnight will resolve the market.