Numerical weather prediction models from the Met Office and European Centre for Medium-Range Weather Forecasts ensembles currently indicate a daytime maximum of 14–15 °C for London on May 16, driven by persistent northwesterly flow, extensive low-level cloud, and light showers that limit insolation. Overnight lows near 5 °C and modest mixing have kept the boundary layer stable, preventing rapid warming despite mid-May solar angles. This setup aligns with the market’s tight clustering around 14 °C (53.5 %) and 15 °C (31.5 %), as traders weigh the latest 06Z/12Z model runs showing limited upside potential. Afternoon observations at London City Airport will refine the exact peak, with any clearing trend the key variable that could nudge the outcome toward 15 °C or hold it at 14 °C.