Recent Met Office and ensemble forecasts indicate a high-pressure ridge delivering sunny skies and light winds across London on September 21, supporting a maximum of 23°C with minimal cloud cover and negligible precipitation risk. This setup follows a brief cool-down on the 20th and aligns with model consensus projecting daytime peaks near or slightly above the long-term September average of about 20°C. Trader emphasis on the 23°C outcome reflects the stability of these guidance runs, while the secondary 22°C probability accounts for minor timing or local measurement variations at official stations. No significant model divergence or frontal systems appear likely to alter the outcome before resolution.