**Trader consensus at 100% on 31°C for Madrid's September 27 daily maximum rests on official surface observations showing the peak reached that threshold under partly cloudy skies and light southerly flow.** Multiple numerical weather prediction runs and agency guidance converged on this value, consistent with late-September climatology for the Madrid region where highs near 30°C are typical absent strong advection or cloud cover. Real-time station data from AEMET-affiliated sites aligned closely with model consensus, leaving minimal room for downward revision. The only realistic challenges involve post-analysis quality control adjustments or microscale differences between reporting stations, though historical verification rates for such clear-cut cases remain high.