Official forecasts from the Met Office and supporting models indicate fine, dry conditions with warm sunny spells and light variable winds across London on October 1, supporting a daytime maximum near or slightly above the seasonal average of roughly 18°C. High pressure and minimal cloud cover have enabled steady warming through midday, with hourly observations and ensemble guidance converging on peaks of 21–22°C as the most probable range. This atmospheric setup, including stable pressure around 1020–1025 hPa and dew points in the low teens Celsius, positions 21°C as the market leader while leaving modest room for 20°C if afternoon cloud increases slightly or for 22°C under optimal insolation. Updated model runs and regional briefings remain the key near-term catalysts for any probability shifts before resolution.