Recent Met Office and European Centre for Medium-Range Weather Forecasts ensemble runs have converged on a London maximum of 13–15 °C for May 16, anchoring the market’s heavy weighting toward 14 °C and 15 °C. Persistent northerly flow across the UK has advected cooler maritime air, limiting daytime heating and keeping temperatures well below the mid-May climatological average of roughly 17 °C at central London sites. Cloud cover and light winds have further suppressed surface warming, with model guidance showing only modest afternoon recovery. Updated 06Z and 12Z runs this morning have tightened the probability distribution within that narrow band, leaving little room for higher outcomes unless a late clearing trend develops beyond current projections.