**Trader consensus clusters tightly around 23–25°C for Mexico City’s August 9 high, reflecting model guidance and climatology for the city’s high-elevation, rainy-season setting.** Mexico City sits at roughly 2,240 m in the Valley of Mexico, where August daytime maxima normally average near 24°C even without strong synoptic forcing. Persistent afternoon convection and cloud cover during the peak of the North American monsoon season typically cap temperatures, keeping the distribution narrow. Recent forecast runs from sources such as the Servicio Meteorológico Nacional and international guidance show a consensus high near 23–25°C for August 9, with some local outlooks allowing brief afternoon readings up to 25–27°C under partial clearing. This directly supports the market-implied probabilities (24°C at 40 %, 25°C at 26 %, 23°C at 25 %). Lower outcomes (22°C and below) receive modest weight from the possibility of heavier or earlier rain, while 26°C or higher remains low-probability because sustained clear, hot conditions are uncommon in early-August climatology. Official maximum-temperature observations from the Servicio Meteorológico Nacional will resolve the market once recorded.