Recent Met Office guidance points to a minimum of 17°C in London on August 10 under mostly clear to partly cloudy skies and light winds, though ensemble models show modest spread around this value. Persistent high pressure has maintained above-average overnight temperatures across southern England this summer, limiting radiative cooling, while any increase in low-level moisture or thin cloud could raise the minimum by 1–2°C. The tight clustering of market-implied probabilities between 18°C and 19°C reflects trader assessment of these boundary-layer uncertainties and the potential for slight forecast revisions before resolution. Historical August minima in London average near 13–14°C, underscoring how current warm nocturnal conditions elevate the distribution. Updated model runs and official briefings over the next 48 hours will likely drive the largest shifts in positioning.