**Trader sentiment for Mexico City's July 20 high centers on the narrow gap between 26°C and 27°C implied probabilities, reflecting model consensus around slightly above the long-term July average of ~24°C.** Official climatology from sources like AccuWeather and WeatherSpark places typical highs at 22–25°C due to the city's 2,240 m elevation and July rainy-season dynamics, where afternoon cloud cover, scattered thunderstorms, and evaporative cooling from rainfall often cap daytime peaks. Recent short-range forecasts and ensemble runs showing reduced precipitation or clearer morning conditions have nudged expectations upward, with traders weighing variables such as dew-point levels, wind patterns from the northeast, and potential model spread in maximum temperature guidance. Historical analogs indicate occasional excursions to 26–27°C when subtropical moisture is limited, while sustained monsoon activity tends to hold readings nearer 24–25°C; resolution hinges on the precise observed maximum at official stations amid these competing influences.