**Forecast models indicate elevated overnight lows for Madrid on September 6, 2026, amid a broader warm spell, yet substantial uncertainty persists around exact minimum temperatures.** Current guidance from sources including globalmeteo, WeatherBug, and Yr.no projects daytime highs of 34–37°C with nighttime minima near 23–24°C under mostly clear to partly cloudy skies and light variable winds. These values sit well above the 1991–2020 climatological average low of 17°C for the date, driven by persistent high pressure, southerly flow advecting warmer air, and limited radiative cooling from urban heat retention and possible residual cloud cover. The near-even split in market-implied odds between a minimum of 31°C or higher (50.0%) and 21°C or below (48.5%) reflects genuine forecast divergence at this 48-hour lead time. Key differentiating factors include potential shifts in wind direction or speed that could enhance or suppress mixing, variations in overnight cloud cover affecting longwave radiation loss, and any late adjustments in the strength of the warm advection. Historical precedent shows September minima can vary widely (record low 9.2°C, recent years often 16–22°C), underscoring how small changes in these variables can shift the outcome. Updated model runs and observational data over the next 24 hours will likely clarify whether the current warm bias holds or yields to modest cooling.