Recent National Weather Service and regional model consensus for Mexico City points to a highest temperature on June 24 near 22–24 °C amid the onset of the rainy season, which has driven the market’s tight clustering around these outcomes. Afternoon convection and increasing cloud cover typically cap daytime maxima several degrees below late-spring peaks, while historical June averages of 24–25 °C and the last week’s observed highs in the same range reinforce this envelope. Updated short-range guidance shows limited day-to-day variability, keeping probabilities for outcomes outside 21–25 °C below 10 % each. Traders are therefore weighting the most likely forecast envelope rather than outlier model runs, with subtle differences in predicted cloud thickness, timing of showers, and boundary-layer moisture determining the narrow spread between 22 °C and 24 °C.