Forecast models from the Met Office and other centers indicate London’s peak temperature on August 17 will likely reach the mid-to-upper 20s Celsius under high pressure, with sunny intervals, light winds, and minimal cloud cover supporting daytime heating after the recent heat spike that peaked near 38°C on August 13. Ensemble guidance shows only modest spread, keeping 26–27°C as the most probable outcomes and limiting chances of 28°C or higher unless insolation strengthens further. Dry conditions and stable steering patterns reduce variability, though any unexpected increase in Atlantic moisture or thicker afternoon cloud could cap readings nearer 25°C. Updated model runs and official briefings tomorrow morning will provide the final refinement before markets settle.