**Forecast models indicate a minimum temperature in Madrid on August 26, 2026, most likely in the 17–19°C range, with market-implied probabilities clustered tightly around 14–18°C reflecting ensemble uncertainty.** Recent cooling follows a warmer-than-average August, with observed overnight lows declining from the mid-20s°C earlier in the month to ~19–20°C by August 24–25. Multiple sources (including GFS-based and official agency guidance) project a low of roughly 17–19°C under partly to mostly cloudy skies, light-to-moderate southwesterly winds, and moderate humidity that limits radiative cooling. Clearer breaks could allow temperatures to dip toward 16–17°C, while increased cloud cover or wind mixing would keep readings closer to 18–19°C. Key scientific factors differentiating the closely matched outcomes include: - **Nocturnal radiative cooling rates** modulated by cloud cover and dew-point depression. - **Advection** from Atlantic air masses. - **Urban heat-island effects** and local topography in the Madrid basin. - **Model spread** in timing of the minimum and boundary-layer mixing. Traders appear to weigh the possibility of a slightly cooler outlier run against the current consensus, producing the observed spread across the lower- to mid-teens and upper teens. New model updates and observational data from the next 12–24 hours will likely narrow the distribution before resolution.