Trader sentiment on Madrid’s October 14 low temperature reflects tight uncertainty in overnight radiative cooling under clear skies and light northeasterly winds. Multiple forecasts cluster the minimum between 13–15 °C, driven by Madrid’s continental climate, 650 m elevation, and modest urban heat-island effect that can raise observed lows by 1–2 °C relative to rural sites. Recent high-pressure dominance and dry air have favored efficient heat loss after sunset, yet small differences in boundary-layer moisture or wind speed across model runs keep the 12 °C-or-below and 13–15 °C outcomes nearly even. Official AEMET and airport observations through dawn will resolve the market as temperatures bottom out before sunrise.