**Forecast uncertainty for the overnight minimum on September 15 is the main driver of the closely matched market odds, with traders split between mild (17°C or higher low at 45.0% implied probability) and notably cooler (7°C or below at 44.5%) outcomes despite model guidance pointing to a more moderate range around 11–15°C.** Current short-range forecasts from sources like GFS and regional models indicate a generally mild early-autumn pattern over Warsaw, with daytime highs near 18–20°C and overnight lows most likely in the 12–14°C range under variable cloud cover, light westerly winds, and possible fog. This aligns with climatological norms for mid-September, when average minima typically fall between 11–14°C as solar insolation declines and radiative cooling strengthens at night. Key scientific factors creating the spread in trader views include model divergence on cloud cover and boundary-layer mixing. Clear skies would enhance longwave radiative heat loss from the surface, potentially driving the minimum lower (favoring outcomes near or below 10–11°C), while increased low-level moisture, fog, or stronger winds could limit cooling and support milder readings. Westerly flow from the Atlantic tends to advect milder maritime air, but any shift toward northerly or easterly components could introduce cooler continental air. Urban effects in Warsaw may slightly moderate the absolute minimum compared to rural sites, though official resolution likely uses a standard meteorological station. With resolution imminent, the next model runs and observational updates on wind, humidity, and cloud trends will be critical in narrowing the implied probabilities around the central temperature bins.