Trader consensus on Polymarket assigns 100% implied probability to a lowest temperature of 14°C in Shanghai on May 4, 2026, reflecting authoritative observational data from the Shanghai Meteorological Observatory and corroborating bulletins from agencies like the Hong Kong Observatory reporting a daily low of 14°C amid overcast-to-sunny conditions. This positioning stems from early-morning measurements capturing the minimum before daytime warming to around 25°C under light southerly winds, consistent with spring climatology where May lows average 15–16°C but vary with cloud cover and urban heat effects. Model ensembles from global forecasts, including those on timeanddate.com and weather.com.cn, aligned precisely on this outcome by midday. Realistic challenges would require unexpected radiational cooling overnight from prolonged clear skies, though current trajectories and residual cloudiness render this highly unlikely before market resolution.