Trader consensus favors 22–23°C as the most likely peak for London on August 20, reflecting the Met Office’s current forecast of a 23°C maximum under light showers and variable cloud. These closely matched probabilities arise from subtle differences in ensemble guidance on afternoon cloud cover, shower timing, and boundary-layer mixing, all of which can shift the realized high by 1–2°C. Atlantic low-pressure influences and residual moisture from earlier warm spells are moderating temperatures below recent peaks, consistent with typical late-summer variability. Updated Met Office and ECMWF runs over the next 48 hours will narrow the range and clarify whether conditions trend toward the upper or lower end of the favored outcomes.