Recent Met Office guidance and ensemble model runs from ECMWF and the UKV highlight a warm, mostly sunny pattern for London on August 8, with daytime maxima forecast near 27–28 °C—well above the 1991–2020 August average of roughly 23 °C. Light winds, limited cloud cover, and urban heat-island effects in central districts support the higher end of guidance, while minor variations in timing of any residual moisture or Atlantic flow create the narrow spread between 26 °C and 29 °C outcomes. Traders are weighting the latest deterministic and probabilistic outputs most heavily, as resolution hinges on the official maximum recorded at the designated London station. Updated model cycles through the weekend remain the key catalyst likely to shift the closely matched 27 °C and 28 °C probabilities.