Recent Met Office forecasts for London on August 4 project a daytime maximum of 28°C, with ensemble models showing a narrow range centered on 27–29°C as a warm air mass begins yielding to more unsettled Atlantic flow. This underpins the tight market clustering, where 29°C holds a slight edge at 36.5% implied probability due to residual high pressure and southerly advection that could sustain peak readings near 29°C before cooling sets in. Key variables include daytime cloud cover, wind shifts, and urban heat-island effects that add 1–2°C locally; historical August maxima average near 24°C, making current conditions unusually warm. Updated model runs and official briefings over the next 48 hours will likely refine these thresholds ahead of market resolution.