**Persistent high-pressure dominance and warm advection from subtropical air masses underpin the tight clustering around 36–37°C for Madrid’s June 30 maximum.** Official guidance from AEMET and ensemble forecasts indicate continued clear skies and strong daytime insolation through the end of the month, following an intense late-June heatwave that produced several days above 38°C. Subtle model spread in boundary-layer mixing and the precise strength of the Iberian high creates the near-even split between 36°C (41.5%) and 37°C (40.0%), with lower probabilities for 35°C or 38°C reflecting uncertainty in whether modest Atlantic moisture or slight wind shifts will cap the peak. Historical June climatology for Retiro station shows typical maxima near 31–32°C, so current conditions represent a clear positive anomaly driven by the amplified ridge. Traders are weighting the latest 48-hour model runs and AEMET updates most heavily ahead of the final 24-hour verification window.