Trader consensus on Polymarket reflects profound uncertainty in Helsinki's highest temperature on April 6, with all outcomes from 0°C or below to 10°C or higher trading at equal 25.5% implied probabilities, as forecast ensembles from the Finnish Meteorological Institute (FMI) show an 80% prediction interval spanning -5°C to 15°C three days out. This stems from early April's transitional weather patterns over the Baltic Sea region, where northerly continental polar air masses could suppress maxima near 0-3°C, while westerly maritime flows enable 6-9°C peaks amid variable cloud cover and light precipitation risks. The FMI's latest run (updated April 2 evening) centers on a 5°C high—aligning with the 5.9°C climatological average—but model divergences in low-pressure positioning and wind shear create the wide spread. Watch daily FMI updates and ECMWF/GFS ensembles for shifts ahead of resolution based on official Helsinki observations.