Latest ensemble forecasts from GFS and ECMWF models project Shenzhen's May 17 high temperature near 27-28°C, driving trader consensus with those outcomes leading at 52.5%, as increased cloudiness and 50-70% shower probabilities from a moist southerly flow cap daytime heating in the Pearl River Delta. Differentiating factors include precipitation timing—persistent overcast skies favor 27°C by suppressing solar insolation, while afternoon clearing could boost urban heat island effects to 28°C; 31°C or higher at 50% reflects outlier dry scenarios reminiscent of May 13's 31°C peak under clearer conditions. Official resolution uses Shenzhen Bao'an International Airport observations; expect refined guidance from today's 12Z model runs and China Meteorological Administration updates. Climatological May highs average 29°C, underscoring short-term uncertainty.