Recent Met Office and European model runs show London's peak temperature on August 28 likely reaching 21–22 °C under a southwesterly flow, with scattered showers and thunderstorms possible during the afternoon. These conditions introduce uncertainty in the exact maximum, as cloud cover, timing of rainfall, and localized convective cells can suppress or briefly elevate readings relative to clear-sky potential. The flat 50 % distribution across bins reflects trader assessment of this narrow forecast envelope around the late-August climatological average of 22 °C at Heathrow, with resolution hinging on official Met Office observations and any last-minute model shifts before the 48-hour window closes.