**Trader sentiment for the lowest temperature in Helsinki on August 28, 2026, centers on 8–9 °C because current numerical weather prediction models and observational trends point to an overnight low in that range.** Forecasts from sources aligned with the Finnish Meteorological Institute and European models indicate daytime highs near 19–20 °C under partly cloudy or clear skies, followed by radiative cooling overnight with light winds (often under 3 m/s) that limit mixing and allow surface temperatures to drop toward 11–14 °C. Coastal moderation from the Baltic Sea typically prevents sharper falls, yet calm conditions and possible clear periods enhance cooling, positioning 9 °C as the mode. Historical late-August climatology for Helsinki shows average minima near 13 °C, so current model consensus reflects slightly cooler-than-normal air masses. Key upcoming data points include updated model runs and official overnight observations from Helsinki-Vantaa Airport, which will determine whether the minimum settles at 9 °C or edges lower to 8 °C under stronger radiational cooling. Market-implied probabilities reflect traders weighting these meteorological factors and the narrow uncertainty band around the forecast minimum.