Trader consensus on a 15°C high for Helsinki on October 2 rests on convergent numerical weather prediction outputs from agencies including the Finnish Meteorological Institute and global models such as GFS. These indicate a mild southerly flow under high pressure, with afternoon temperatures peaking at 15°C amid mostly cloudy skies, light winds, and negligible precipitation. Historical October climatology for southern Finland supports such values as typical rather than extreme. Resolution hinges on official daily maximum observations; while model agreement is strong, minor revisions in final station data or localized microclimate effects could still shift the recorded peak by 1°C in either direction before markets settle.