Forecast models for Karachi on September 1 indicate overnight lows near 26–27°C under partly cloudy skies, light southwesterly winds, and high humidity typical of the late monsoon transition, producing the tightly clustered market odds around 24–28°C. Radiative cooling at night remains limited by persistent moisture and cloud cover that reduces heat loss, while any breaks in clouds or slight wind shifts could allow temperatures to dip toward 24°C or hold near 28°C. Historical September minima average 25–26°C with modest interannual variability, and current ensemble guidance shows limited spread without strong steering patterns or incoming disturbances to alter the baseline. Traders weigh these factors against the two-day lead time until resolution, as small changes in dew point or wind speed near dawn can shift the recorded low across multiple outcome thresholds.