Trader consensus on Polymarket overwhelmingly favors a highest temperature of 25°C at Shanghai's Xujiahui observatory—the market's key resolution station—as reflected in the 100% implied probability, driven by the China Meteorological Administration's (CMA) midday forecast update projecting exactly this peak under persistent overcast skies and light winds that suppress solar heating. This aligns with ensemble guidance from ECMWF and GFS models clustering at 24–26°C, early-morning observations near 14°C, and May climatological norms around 23°C amid East China's spring patterns. Current readings, including mid-afternoon peaks at approximately 25°C (77°F), reinforce this positioning. Unexpected clearing could enable brief spikes to 26°C, while increased cloudiness or northerly flows might cap it below; final intraday observations from CMA will resolve by evening.