Trader consensus on Polymarket closely splits between 19°C (31.5%) and 20°C (31.0%) for Shanghai's lowest temperature on May 14 at Pudong International Airport, reflecting ensemble forecast models like GFS and ECMWF projecting overnight lows near 19.5–20°C amid persistent cloud cover and 40–45% chance of passing showers. These conditions limit nocturnal radiative cooling by trapping heat, while moderate humidity around 50–55% and southerly winds temper further drops, differentiating the outcomes—clearer skies could dip to 19°C, fuller overcast holding at 20°C. Recent model runs over the past 24 hours show slight cooling from prior 21°C estimates due to incoming moist air mass. Watch China Meteorological Administration updates and hourly observations starting late May 13 for resolution shifts, as typical mid-May baselines hover 18–20°C with high forecast uncertainty at 48-hour range.