Current numerical weather prediction ensembles place Shanghai’s June 12 overnight minimum most likely between 21 °C and 23 °C, consistent with the tightly bunched market-implied probabilities. Increasing cloud cover and scattered light rain tied to the early East Asian summer monsoon (plum rain) are limiting radiational cooling, keeping lows several degrees above the clearer-sky values seen earlier in the month. Southerly flow is also advecting slightly warmer, more humid air, while historical climatology for the first half of June shows average lows near 20–21 °C. Short-term model updates from the China Meteorological Administration over the next 48 hours will determine whether any further moderation or brief clearing shifts the distribution within the narrow 20–24 °C band.