Current forecast models and official guidance position 27°C as the leading outcome for Mexico City’s August 4 maximum, with traders assigning it a 55.5% implied probability amid convergence on the 26–28°C range. At 2,240 m elevation, thinner air and frequent afternoon convection during peak rainy season typically cap daytime highs near the long-term August average of 24–26°C, where partial morning sunshine gives way to scattered thunderstorms that limit further warming. Recent model runs align closely with yesterday’s observed 27°C peak, reinforcing this narrow band while residual uncertainty around cloud timing and localized heating supports modest shares for 26°C and 28°C. Updated observational data and afternoon model revisions will clarify any late shifts before resolution.