**Trader consensus in the Mexico City lowest-temperature market centers on 13–14°C outcomes, reflecting official forecasts and observed conditions shaped by the city’s high-elevation basin setting (roughly 2,240–2,300 m).** Persistent cloud cover and scattered showers from the Mexican monsoon and tropical waves limited nighttime radiative cooling on September 9, keeping the minimum from dropping below the seasonal norm of about 13–15°C. Hourly data and station reports showed overnight lows reaching approximately 12–14°C amid overcast skies and light rain, while daytime highs climbed to 22–25°C under partly clearing conditions. These factors aligned with pre-event National Meteorological Service guidance of a 13–15°C minimum, producing the current market-implied probabilities that heavily favor the 13–14°C range over colder extremes. Resolution will depend on the final verified station reading, with any late adjustments to model consensus or observational data capable of shifting the exact threshold.