Recent ensemble forecasts from the European Centre for Medium-Range Weather Forecasts and Global Forecast System show Shanghai's May 19 overnight low centered near 20°C, with model spreads producing nearly equal implied probabilities across 19–21°C. Light southeast winds and variable cloud cover over the East China Sea are expected to moderate radiative cooling, keeping temperatures close to the mid-May climatological average of 18–21°C. Persistent high-pressure ridging limits cold-air advection, while subtle differences in humidity and boundary-layer mixing could shift the minimum by 1–2°C. Official China Meteorological Administration guidance and surface observations through May 18 will refine the final range ahead of resolution at Shanghai Pudong International Airport.