Trader consensus on Polymarket clusters implied probabilities tightly around 14–18°C for Helsinki's highest temperature on May 8, driven by short-range forecast ensembles from the Finnish Meteorological Institute (FMI), ECMWF, and GFS models showing a mean peak near 16°C amid inherent 48-hour uncertainty. Recent FMI observations note cool highs of 7–9°C under southwest winds and partial cloudiness, but models project southerly flow and a building high-pressure ridge over Scandinavia to boost daytime heating, tempered by the cold Baltic Sea surface temperatures around 5°C. Differentiating factors include model spreads on cloud amount—clearer skies favor 17–18°C via greater insolation, while overcast conditions cap at 14–15°C—and wind shear effects on boundary-layer mixing. Updated FMI bulletins and ECMWF runs due within 24 hours will sharpen this outlook.