Trader consensus on Polymarket reflects a tight cluster of implied probabilities around 22–24°C (21–22% each) for Mexico City's highest temperature on April 5, driven by the latest GFS and ECMWF ensemble forecasts projecting daytime highs in this below-normal range amid lingering cooler air from a recent frontal passage. The high-altitude basin (2,240 meters) typically sees April averages near 26°C, but northerly winds and mid-level clouds from the subtropical jet stream are suppressing convective heating and boundary layer mixing, as confirmed by Servicio Meteorológico Nacional observations over the past 48 hours of partly cloudy conditions and subdued highs. Model spread highlights uncertainty in afternoon clearing—persistent overcast favors 22°C, while subsidence could push toward 24°C—with key differentiation from upcoming 00z/12z runs and SMN briefings expected before resolution.