Traders have converged on a 13°C daily maximum for Helsinki on October 3 because official observations and model consensus from sources such as the Finnish Meteorological Institute and global ensembles show the temperature peaking at that level under a stable high-pressure regime, light southwesterly winds, and predominantly overcast conditions that limited solar heating. Hourly data indicate afternoon readings reached or approached 13–14°C before cooling into the evening, aligning with climatological expectations for early October in southern Finland. This strong scientific agreement and proximity to day’s end leave little room for revision. Only an unexpected late surge in insolation or an unforecasted warm advection could realistically push the official maximum to 14°C or above, though current monitoring shows no such deviation.