Current forecast models from sources including NOAA-aligned and European ensembles project Mexico City’s overnight low on September 30 near 13–14 °C, aligning with the city’s typical late-September climatology at 2,240 m elevation amid persistent cloud cover and light rain. These conditions limit nocturnal radiative cooling while daytime heating remains modest under overcast skies. Trader sentiment remains nearly evenly split between sub-8 °C and 18 °C+ outcomes because short-range model runs still show modest spread in boundary-layer moisture and wind patterns that could shift the minimum by several degrees. Updated model guidance expected overnight will likely tighten the distribution ahead of the 24-hour observation window used for market resolution.