Current ensemble forecasts from the European Centre for Medium-Range Weather Forecasts and Météo-France project overnight lows in Paris for May 20 centered around 10–13°C at the Le Bourget reference station, with a broad spread reflecting uncertainty in cloud cover, wind patterns, and any residual Atlantic frontal activity. This distribution supports the market’s elevated pricing on 16°C or higher alongside clustered probabilities near 11–12°C, as traders weigh the potential for a clear, calm night versus modest cooling under variable May conditions. Climatological baselines for mid-May show typical lows near 9–10°C, but recent model runs highlight sensitivity to subtle steering changes that could shift outcomes by several degrees. Updated high-resolution guidance and observational data over the next 48 hours will further refine these probabilities ahead of resolution.