Recent Met Office and GFS model runs indicate a mild southwesterly flow over southern England, positioning London for a daytime high of 24–26°C on September 3. This air mass, drawn from the Atlantic, limits daytime heating while increasing cloud cover and humidity, keeping values near seasonal norms rather than allowing stronger insolation or continental warmth. Ensemble guidance shows limited spread, with most solutions converging on afternoon peaks around 25°C under partly cloudy skies and light winds. Traders have priced these outcomes highest because successive model updates through early September have reinforced this range, with only modest upside risk from any unexpected ridge development. New forecast cycles and observational data over the next 48 hours will determine whether probabilities shift toward 24°C or 26°C.