Current ensemble forecasts from the Met Office and ECMWF place London's July 18 maximum near 23–26 °C, with 24 °C holding the highest implied probability as models converge on modest Atlantic-driven cooling after earlier July warmth. Key differentiating factors include the timing of a weak frontal passage, variable cloud cover that limits solar heating, and boundary-layer moisture affecting the afternoon peak. Small shifts in low-level wind direction or clearance of stratiform cloud can swing the daily high by 1–2 °C, explaining the tight clustering around 24–26 °C while lower and higher outcomes remain marginal. Updated model runs and Met Office guidance on July 17 will further refine these probabilities ahead of resolution.