Forecast models from sources including the National Meteorological Service and international ensembles point to an overnight low in Mexico City on August 27 in the 12–15 °C range, driven by the city’s 2,240 m elevation that promotes efficient radiative cooling after sunset under partly cloudy skies typical of the late-summer rainy season. Light northerly winds and moderate humidity (around 70–90 %) limit extreme drops, while scattered showers or increased cloud cover could trap heat and keep readings near 14–15 °C; clearer breaks would favor 12–13 °C. These values align closely with August climatology (average low near 13–14 °C) and recent station observations of 13–14 °C, producing tightly bunched market probabilities as traders weigh minor differences in model timing and boundary-layer moisture.