Recent ensemble forecasts from the Met Office and European Centre for Medium-Range Weather Forecasts indicate a mild spring airmass over southern England through May 20, with the daily minimum temperature most likely settling between 10 °C and 13 °C. Overnight radiative cooling under partly cloudy skies and light winds from the southwest should limit further drops, while a weak warm front approaching from the Atlantic may raise the floor slightly. Historical May climatology for London shows average minima near 9 °C, yet current model consensus places the outcome above this baseline due to suppressed northerly flow and above-normal sea-surface temperatures in the North Sea. The tight clustering of market probabilities around 12 °C and 13 °C reflects uncertainty in exact cloud cover and boundary-layer mixing on the final day, with new model runs expected to narrow the range as the period draws closer.