Forecast models indicate Mexico City's overnight low on August 26 will likely fall between 12–13°C, reflecting the city's 2,240 m elevation and typical late-summer radiative cooling under variable cloud cover during the rainy season. Light northerly winds and high humidity limit mixing and heat loss, keeping temperatures above the 9–11°C range seen in clearer conditions, while scattered storms and thick clouds prevent sharper drops to 15°C or higher. Trader clustering around 12–15°C outcomes stems from minor model differences in cloud timing and wind patterns that alter the precise minimum by 1–2°C. Official station data and updated runs will resolve the exact value by morning.