**Trader sentiment for the lowest temperature in Mexico City on August 29, 2026, clusters tightly around 12–15°C (each near 26% implied probability), reflecting forecast uncertainty in the exact pre-dawn minimum amid ongoing rain and variable cloud cover.** Official Servicio Meteorológico Nacional guidance points to a minimum of 13–15°C, consistent with several models showing early-morning readings near 10–14°C under mostly cloudy, rainy conditions. Persistent showers and thunderstorms (70–85% probability) limit nocturnal radiative cooling at the city’s high elevation (~2,240 m), while light winds and high humidity further moderate temperature drops compared to clearer nights. Historical climatology for late August shows typical lows near 14°C, with the urban heat island and orographic effects adding variability across stations. Model spreads arise from differences in boundary-layer mixing and precipitation timing, keeping probabilities for 11°C or below (under 25% combined) and 16°C+ (under 32% combined) lower. Recent hourly observations dipping to 10–11°C overnight support the balanced market pricing around the central range, with resolution hinging on the precise official minimum recorded at the primary reference station.