Recent forecasts from the Finnish Meteorological Institute and European models indicate overnight lows near 13°C in Helsinki on August 21, shaped by moderate southwesterly flow, partial cloud cover, and limited radiative cooling under a stable maritime air mass. Trader consensus clusters around 11–12°C because boundary-layer mixing, exact cloud timing, and dew-point depression introduce 1–2°C uncertainty in minimum temperatures. Clearer skies overnight would enhance longwave radiation loss and push readings toward 9–10°C, while increased wind or lingering clouds would limit cooling and favor 12°C or higher. These factors align with typical late-August climatology, where average minima hover near 10–11°C, leaving resolution dependent on final observational data from Helsinki-Vantaa.