Recent forecast models from agencies including the Japan Meteorological Agency and international ensembles indicate an overnight low in Tokyo on August 31 most likely between 23–25°C, driven by lingering cloud cover, elevated humidity near 90 percent, and light northeasterly winds that limit radiational cooling. Recent heavy rainfall and a passing frontal system have kept surface temperatures suppressed relative to seasonal normals, while the urban heat island effect in central Tokyo may prevent the lowest readings from falling as far as rural analogs. With leading market-implied probabilities closely split between 24°C and 25°C, traders appear focused on the precise timing of any clearing skies in the final 48 hours, as even modest increases in wind or dewpoint depression could shift the minimum by 1–2°C.