Trader consensus on Polymarket closely splits between 12°C (51%) and 11°C (44.5%) for Tokyo's lowest temperature on May 1, reflecting model spread in Japan Meteorological Agency (JMA) guidance and global ensembles like ECMWF and GFS, which project an overnight minimum near 11.5°C under partly cloudy skies and light winds favoring radiative cooling. Recent 24-hour model runs show minimal shifts, with no major developments like fronts in the past week; instead, springtime upper-air patterns dictate a cooler-than-average airmass post-April variability. Differentiating factors include nocturnal cloudiness degree and dawn timing of the low at Tokyo's official station, where urban heat island effects typically buffer 1°C above rural readings. JMA's next 00Z forecast update will likely clarify before resolution.