Forecast models from sources including GFS and regional analyses show Warsaw under building high pressure on September 26, with light southwesterly flow, extensive low- to mid-level cloud cover, and minimal warm advection. These conditions support a daily maximum near 17–18 °C, consistent with late-September climatology and limiting daytime heating despite clear-model trends overnight. Recent runs have converged on this narrow range, with only modest spread from slight variations in cloud timing or boundary-layer mixing. Traders have therefore assigned the highest implied probabilities to 18 °C (54.5 %) and 17 °C (35.5 %), reflecting the strong consensus in official guidance and the low likelihood of outliers given the stable synoptic pattern.