Latest Met Office guidance points to a 28°C high in London on August 10 under strengthening high pressure, with warm-air advection and clear skies supporting peak insolation. Ensemble spreads create tight clustering around 26–28°C because minor variations in cloud cover, boundary-layer mixing, or the precise track of the anticyclone can shift maximum temperatures by 1–2°C. Recent model runs show consensus on above-average warmth but diverge on afternoon convective development that could cap readings near 26°C or allow full 28–29°C realization. Traders therefore assign nearly equal weight to the leading outcomes, reflecting the narrow but physically meaningful uncertainty range in official short-range forecasts.