Recent forecast models from the Met Office and ECMWF indicate a mild nocturnal regime for London on 19 August, with westerly to southwesterly flow, variable cloud cover, and limited radiative cooling expected to hold the daily minimum near 15–17 °C at urban stations. A developing northerly component may introduce slightly cooler maritime air later, yet residual warmth from recent above-average conditions and urban heat-island effects support the market’s heavy weighting toward 17 °C. Ensemble spreads remain narrow around these values, with only modest downside risk to 15–16 °C if clearer skies develop overnight; upside to 18 °C appears limited absent stronger warm advection. Updated model runs and Met Office briefings tomorrow morning represent the key data points likely to refine these implied probabilities before resolution.