**Forecast models indicate a mild overnight minimum for Helsinki on August 31, 2026, with the lowest temperature most likely settling near 15–16°C.** Southerly to southwesterly winds around 10–15 km/h, combined with persistent cloud cover and high humidity (often 90%+), are limiting radiative cooling and keeping surface temperatures elevated above the long-term average low of roughly 12°C. Current runs from sources like the Finnish Meteorological Institute and international models show daytime highs near 18–19°C under mostly cloudy, showery conditions, followed by gradual overnight stabilization around 15–16°C. The near-even split in market-implied odds between 15°C and 16°C reflects typical model spread in the exact timing of any partial clearing or wind lull, which could nudge the minimum by 1°C either way. Lower probabilities for 14°C or below align with the absence of stronger northerly flow or clearer skies that would enhance cooling. Traders are weighting the latest ensemble guidance showing a stable, relatively warm airmass in place through the resolution window.