Recent meteorological model runs from the Finnish Meteorological Institute and ECMWF ensembles indicate southerly airflow advecting milder Atlantic air masses into southern Finland, positioning Helsinki-Vantaa Airport’s maximum temperature for May 17 near 16–17 °C under partly cloudy skies and light winds. This places 16 °C (41.5 % implied probability) and 17 °C (30.0 %) as the leading outcomes, modestly above the May climatological average of 14–15 °C. Subtle forecast spread in afternoon boundary-layer mixing and high-cloud timing creates the tight clustering around these two bins, while lower probabilities for 15 °C or 18 °C reflect limited downside risk from lingering marine influence and constrained upside from modest solar insolation. Updated short-range guidance tomorrow morning will further refine the peak.