Tokyo's mid-August temperatures typically peak near 30–31°C under the influence of the North Pacific high, though recent model runs for August 16 point to a narrow range centered on 29–30°C due to variable cloud cover and scattered showers that can suppress daytime maxima by 1–2°C. Urban heat-island effects in the Tokyo metropolitan area add a consistent 1–3°C boost relative to rural baselines, while high humidity does not alter measured air temperature but influences local energy balance. Short-term ensemble forecasts from agencies such as the Japan Meteorological Agency show limited spread, with the 28–31°C band accounting for most probability; any shift in steering flow or timing of rain bands could tip the daily high between the two leading outcomes.