Trader sentiment centers on a 17°C low for Tokyo on May 18, reflecting Japan Meteorological Agency model consensus for stable high pressure over the Kanto Plain that supports radiative cooling under mostly clear skies and light winds. This aligns with mid-May climatology, where overnight minima typically range 14–17°C. Higher outcomes near 19–20°C gain traction if a warmer air mass advects northward or persistent cloud cover limits cooling, while lower readings around 16°C or below would require sharper clearing or a brief frontal passage. Key variables include forecast model spread on dew-point depression, wind mixing overnight, and any late adjustments to the subtropical ridge position ahead of the weekend. New JMA updates and ensemble runs expected in the next 48 hours will likely tighten probabilities around the official station reading at Haneda or Otemachi.