Recent high-pressure building over the UK has brought settled, mostly clear conditions to London, favoring radiative cooling overnight on June 14–15 and producing minimum temperatures clustered near seasonal norms of 12–14°C. Light winds and limited cloud cover enhance surface heat loss, while the urban heat island effect and residual warmth from recent days limit further drops; Met Office guidance points to a 15°C daytime maximum with overnight values near 13°C under these stable patterns. Ensemble model outputs show tight clustering around this range with modest spread from small variations in boundary-layer mixing and residual moisture, explaining why traders assign nearly equal weight to the 12°C and 13°C outcomes while discounting extremes below 11°C or above 14°C. Updated guidance and any late shifts in cloud or wind forecasts over the next 24 hours remain the key variables that could tip the final recorded low.