**Mild southwesterly flow and persistent cloud cover are keeping overnight radiative cooling limited, producing forecast minimums clustered around 14–17°C for London on September 2.** Official guidance from the Met Office and ensemble models shows a moist Atlantic airstream with broken to overcast skies and light-to-moderate southwest winds overnight, suppressing the clear-sky temperature drop that would otherwise push readings into the low teens. Recent model runs have converged on 15–16°C as the most probable minimum, reflected in the tight market split (39% for 16°C, 36.5% for 15°C). Slight variations in cloud timing or wind strength could shift the outcome by 1°C in either direction, which is why 14°C and 17°C still command meaningful probability. Historical early-September climatology places the typical minimum near 13–14°C, so the current pattern represents a modest positive anomaly driven by the ongoing unsettled regime rather than a blocking high. Updated short-range forecasts and observational data from the London area in the next 12–24 hours will determine whether the minimum settles at 15°C or 16°C.