Trader consensus centers on 31°C as Shanghai’s highest temperature on June 3 because current National Meteorological Center guidance and ensemble model runs project a daytime peak in that narrow range under stable subtropical high-pressure influence. Early June conditions feature moderate humidity and light winds typical of the onset of the Meiyu period, with no incoming cold fronts or tropical systems expected to alter the thermal profile before sunset. Historical June maxima for the date average near 29–30°C, providing climatological support. A late-afternoon thunderstorm cell or revised observational data from urban stations could still shift the recorded high by 1–2°C, though such adjustments remain low-probability given the convergence of current guidance.