Recent ensemble forecasts from the ECMWF and GFS models have converged on a maximum temperature of 12–13°C for Warsaw on May 17, anchoring the leading market-implied probabilities at 38% for 13°C and 22% for 12°C. Persistent cool northerly airflow across central Poland, combined with lingering low-level cloud cover, has suppressed daytime heating well below the mid-May climatological average high near 19°C. Minor differences in model timing for partial clearing or wind shifts sustain the tight spread between these two outcomes, while the 26% probability on 14°C and 16% on 15°C or higher capture residual upside risk if solar insolation increases more than projected. Traders are closely monitoring the final 24-hour model runs ahead of official observations at Warsaw Chopin Airport.