Recent high-pressure dominance across southern England, combined with a warming airmass and mostly clear skies, has driven trader consensus toward overnight minima of 18–19°C in London on August 10. Under these conditions, strong radiative cooling overnight is tempered by residual warmth from daytime highs near 27–29°C and the urban heat island effect, which typically adds 1–2°C to city-center lows compared with rural sites. Ensemble guidance from the Met Office and ECMWF shows tight clustering around 17–19°C, with minor spread arising from subtle variations in cloud cover and wind speed that could either enhance or suppress cooling. Historical August climatology supports this range, though the current settled pattern slightly elevates the odds for the higher end of the distribution.