Official Met Office forecasts for London on August 16 project a daytime maximum near 27°C followed by an overnight minimum of 16°C, with similar guidance from BBC and other models showing 15–17°C lows. This positioning stems from a post-heatwave transition featuring lighter northerly winds, variable cloud cover that limits daytime heating yet allows moderate nocturnal radiative cooling, and a shift toward fresher Atlantic air masses replacing the prior warm, stable high-pressure regime. Ensemble guidance indicates limited model spread around these values, with clear spells overnight supporting the 16–17°C range as the most probable outcome while slight variations in cloud timing or wind could nudge readings one degree either way. Updated short-range model runs and Met Office briefings over the next 48 hours will provide the key data for refining these market-implied odds.