**Forecasts from the Met Office and other models indicate a highest temperature in London on August 29 most likely between 20–22 °C, with showers and moderate southwesterly winds expected to limit daytime heating.** Unsettled Atlantic air is driving the pattern, bringing widespread cloud cover, periods of rain or thundery showers (especially from late morning onward), and reduced solar radiation compared with the clearer, warmer conditions seen earlier in August. Official guidance points to a daytime maximum near 22 °C under mostly cloudy skies, with actual peaks potentially held to 20–21 °C if showers arrive earlier or prove heavier. This aligns with the market’s heavy weighting toward 21 °C (44 %) and 20 °C (31 %), while the modest 22 °C probability (14 %) reflects residual uncertainty in shower timing and any brief breaks of sun. Historical late-August averages for London hover around 20–22 °C, so current guidance sits close to climatology but is tempered by the active frontal system. Updated model runs and Met Office briefings through the evening of August 28 will be the key near-term drivers for any shifts in implied probabilities before resolution.