Current short-range forecasts from regional models indicate a Zhengzhou overnight low of 23–25 °C on 22 August under partly cloudy skies, light northeasterly flow, and surface dew points near 22 °C that suppress radiative cooling. These conditions produce the tight clustering of market probabilities around 22–25 °C, as modest increases in cloud cover or scattered drizzle would retain heat and favor the upper end while clearer breaks could allow an extra degree of cooling toward 22 °C. Historical August climatology shows typical minimums near 22–24 °C with low day-to-day variance, so the narrow spread reflects limited forecast uncertainty rather than any unusual atmospheric setup. Updated model runs overnight will refine the exact threshold.