Current forecast models from agencies like the National Meteorological Service position Mexico City’s August 13 maximum near 25–26°C, driving the tight market split between those two outcomes. At the city’s 2,240-meter elevation, the peak of the rainy season brings afternoon convective clouds and scattered showers that routinely limit solar heating and cap daytime peaks. Long-term August climatology shows average highs around 24°C, with recent observations fluctuating 23–26°C due to variable moisture and thunderstorm timing. Model runs differ modestly on exact cloud cover and precipitation onset, creating the close 36%–31% implied probabilities for 25°C versus 26°C while lower and higher thresholds remain less likely.