Recent ensemble forecasts from the Finnish Meteorological Institute point to a peak temperature in Helsinki on May 19 likely falling between 19–23 °C, with the tight clustering of market-implied odds around 20–22 °C reflecting modest uncertainty in afternoon boundary-layer mixing and cloud cover. Springtime radiative heating over the Baltic region, combined with weak southerly flow, favors temperatures near or slightly above the late-May climatological mean of 15–17 °C at Helsinki-Vantaa, yet variable low-level stratus and timing of the diurnal maximum introduce spread across model solutions. Traders are weighting the latest high-resolution runs that resolve these factors most accurately, as small shifts in insolation or wind speed can easily move the daily high by 1–2 °C. Updated FMI guidance and ECMWF ensemble output expected within the next 24 hours will further narrow the range ahead of market resolution.