Latest Japan Meteorological Agency and global model ensembles, including GFS and ECMWF, project Tokyo's highest temperature on April 18 clustering around 20-22°C under a mild southerly flow and weak high-pressure ridge, fueling tight trader sentiment with 34% implied odds on 21°C, 28.5% on 20°C, and 19.5% on 22°C. Overcast conditions in recent runs, like timeanddate.com's 71°F (22°C) outlook with clouds, differentiate outcomes by limiting solar insolation and peak heating compared to clearer skies that could nudge toward 22°C or higher. Above-normal spring anomalies persist from recent 21°C readings on April 16, but 1-2°C model spread reflects uncertainty in cloud cover and frontal timing. Watch JMA's daily update this afternoon for refined guidance ahead of resolution via official observations.