Recent Met Office guidance and ensemble models indicate London’s overnight minimum on August 18 will likely settle near 16–18 °C under sunny intervals, light easterly winds, and stable high pressure that limits radiative cooling after daytime highs around 27 °C. The urban heat-island effect, combined with the lingering warmth from the recent heat spike (prior nights near 18 °C), keeps actual city readings several degrees above rural climatological averages of 13–15 °C. Market pricing at 18 °C (45.5 %) and 19 °C (35.5 %) reflects this consensus, tempered by minor model spread and potential for slightly clearer skies that could nudge the low a degree lower. Updated short-range runs and the final 24-hour forecast before resolution remain the key near-term drivers.