Forecast models for Mexico City on August 13 point to a daytime high near 25–26°C, consistent with the closely matched market-implied odds for those two outcomes. At the city’s elevation of roughly 2,240 meters, strong solar heating is offset by thinner atmosphere and rapid radiational cooling, while the ongoing rainy season promotes afternoon convection that limits peak temperatures through increased cloud cover and evaporative cooling. Recent extended forecasts from sources such as the Met Office and timeanddate.com show 25–26°C maxima with scattered showers possible, keeping values within the historical August range of 23–26°C. Minor differences between 25°C and 26°C hinge on the exact timing and coverage of precipitation versus periods of sunshine, factors that numerical weather models continue to refine as the date approaches.