Current forecasts from the Japan Meteorological Agency indicate mostly cloudy conditions for Tokyo on June 13 with daytime highs near 27°C and overnight lows around 18°C, consistent with the seasonal transition toward higher humidity and temperatures during the tsuyu period. This aligns with the market's heaviest weighting toward 19–21°C or warmer minima, reflecting typical early-to-mid June climatology where average lows range 18–21°C amid moderating Pacific influences. Recent cooling from a lingering frontal system earlier in the week has given way to gradual warming, reducing downside risk for sub-18°C readings while model consensus shows limited variability in steering patterns or cold-air advection that could drive sharper drops. Updated JMA guidance and ensemble runs in coming hours will further refine overnight minimum expectations ahead of the June 13 observation window.