Recent forecast models for Helsinki show overnight lows on September 25 clustered around 9–12 °C amid northerly flow and variable cloud cover, creating the tight market split between sub-5 °C and 15 °C-plus outcomes. Persistent mild conditions through mid-September, with only isolated cooler nights earlier in the month, have kept trader focus on whether a transient ridge or incoming moisture will suppress radiative cooling enough to hold minimums above 10 °C or allow clearer skies and lighter winds to push readings lower. Official guidance from the Finnish Meteorological Institute and ensemble spreads highlight modest uncertainty in exact timing of any showers and boundary-layer mixing, directly influencing the 20 % probabilities assigned to intermediate temperature buckets. Updated high-resolution runs expected within the next 24 hours will likely sharpen resolution criteria around the daily minimum.