Recent ensemble forecasts from the ECMWF and GFS models have converged on a daily high of 12–13°C for Warsaw on May 17, driving the tight clustering of market-implied odds around these outcomes. Persistent cool northerly airflow across central Poland, combined with lingering low-level stratiform cloud cover, has suppressed daytime heating well below the mid-May climatological average near 19°C. Minor differences in model timing for any partial clearing or slight wind shifts create the narrow spread between 12°C and 14°C, while the modest probability on 15°C or higher reflects residual upside if solar insolation exceeds current projections. Traders are closely monitoring the final 24-hour model updates ahead of official resolution by observations at Warsaw Chopin Airport.