Recent forecasts from multiple models indicate Madrid will experience clear skies and light winds on September 22, favoring strong nocturnal radiative cooling that typically produces minimum temperatures near the long-term average of 14.5°C. High-pressure dominance with dry air and minimal cloud cover enhances surface heat loss overnight, while daytime maxima around 32°C reflect continued late-summer warmth. The near-even split between 14°C-or-below and 24°C-or-higher outcomes in trader pricing reflects genuine uncertainty in the precise overnight low, driven by small differences in boundary-layer mixing, urban heat-island effects, and the exact timing of any subtle wind shifts that could limit cooling. Updated model runs closer to the date will likely resolve whether conditions support a dip to or below 14°C versus a milder minimum.