Forecast models from sources like ECMWF and AEMET indicate a September 29 minimum in Madrid near 15–16°C, with moderate uncertainty from variable cloud cover and light southerly winds that limit nocturnal radiative cooling. This spread underpins the balanced 50% implied odds on 12°C-or-below versus 22°C-or-higher outcomes, as modest increases in humidity or thicker low-level clouds could suppress the low by 2–3°C while clearer skies allow greater overnight drops. Historical climatology shows an average low of 13.4°C for the date, providing context for why traders weigh both cooler Atlantic-influenced scenarios and residual warmth from recent high-pressure patterns. Updated model runs and AEMET briefings over the next 48 hours will likely narrow the range ahead of resolution.