Trader consensus on Polymarket reflects high uncertainty in short-term forecasts for Guangzhou's highest temperature on April 17, with implied probabilities tightly clustered around 26–35°C as global models diverge from local guidance. The Guangzhou Observatory's latest 7-day outlook, issued April 14, projects a daytime high of 27°C under partly cloudy skies with light southerly winds and low precipitation risk, consistent with the month's +3.4°C temperature anomaly above the April climatological average of 22.5°C mean. However, ECMWF and GFS ensembles suggest slightly warmer peaks near 31°C due to persistent subtropical high pressure and urban heat effects, while recent observations show highs of 29.6°C on April 10 and 13. New model runs and April 16 observations could sharpen the outlook before resolution.