**Trader sentiment for the lowest temperature in Helsinki on October 13, 2026, centers on a narrow range around 2–4°C, with 4°C holding a slight edge at 51% implied probability and 2°C/3°C near 49.5%.** Lower outcomes like 0°C or below sit at 45%, while anything 5°C or higher is near 0.1%, reflecting consensus that overnight radiative cooling under mostly cloudy to overcast skies will push the minimum into the low single digits Celsius. Official forecasts from sources like the Finnish Meteorological Institute (Ilmatieteen laitos), Yr.no, and GFS-based models show daytime highs of 7–9°C with light northeast to variable winds and high pressure near 1023 hPa. Overnight, temperatures are projected to bottom out near 4–5°C (roughly 40–41°F) as cloud cover limits but does not fully prevent heat loss. Helsinki’s coastal Baltic location provides some moderation compared to inland areas, while minimal precipitation and stable steering patterns reduce volatility. The tight spread between 2–4°C outcomes stems from typical model spread in minimum temperature forecasts, differences in exact observation timing or station microclimate (e.g., Helsinki-Vantaa Airport vs. urban sites), and uncertainty in cloud timing or wind mixing that could allow a few tenths of a degree more or less cooling. No major synoptic changes occurred in the past 24–48 hours to shift the outlook dramatically, keeping probabilities closely matched.