**Latest forecasts from AEMET and numerical models show Madrid’s daily maximum temperature on September 30, 2026, most likely peaking near 27–29 °C under southerly flow, partial afternoon clearing, and light winds.** Official guidance and ensemble runs place the most probable range at 25–28 °C, with modest warming from diurnal heating and reduced cloud cover in the afternoon supporting the market’s strong preference for 29 °C (71 % implied probability). Higher outcomes at 30 °C remain possible if insolation increases more than expected, while 28 °C retains secondary support (21.5 %) if marine influence or lingering morning cloud persists. Resolution will hinge on the official maximum recorded at the Retiro or Barajas reference station, with final verification typically available within 24–48 hours of the close of the calendar day.