Official temperature observations from the Finnish Meteorological Institute confirmed a daily maximum of 13°C in Helsinki on September 25, aligning with the market's near-certain consensus. This outcome reflects typical late-September conditions under moderate high-pressure influence, with clear skies and light winds limiting daytime warming while preventing significant cooling. Historical September averages for the city hover near 14–15°C, making the recorded value consistent with seasonal norms rather than an outlier. Measurement protocols using calibrated sensors at representative urban stations provide high reliability, though rare post-processing revisions or microclimate discrepancies at specific sites could theoretically adjust the official figure by 1°C.