Recent Met Office and ECMWF ensemble forecasts show London maximum temperatures on July 3 most likely peaking near 26–27 °C, producing the tightest implied probabilities at 24.5 % and 29.0 %. A building high-pressure ridge with light southerly flow and limited cloud cover supports daytime warming above the July climatological average of 22 °C, yet small differences in timing of any Atlantic front or boundary-layer mixing keep the two outcomes nearly matched. Traders are weighting the latest model runs most heavily, as forecast uncertainty narrows rapidly with the 48-hour window; the next official update cycle will likely sharpen resolution criteria around the exact daily maximum.