Current numerical weather prediction models and official guidance from the Finnish Meteorological Institute, Met Office, and BBC Weather converge on a daytime maximum near 20°C for Helsinki on August 13, driven by moderate northwesterly flow, partly cloudy skies with sunny intervals, and typical late-summer Atlantic air masses. This positions the 20°C outcome as the leading market-implied probability at 49.5%, with 21°C and 19°C bins capturing the main uncertainty range tied to variable cloud cover and minor timing shifts in any showers. Historical mid-August averages near 19°C provide climatological context, while the absence of blocking highs or strong advection keeps probabilities for extremes below 1%. Fresh model runs and real-time observations tomorrow morning will refine the final maximum before market resolution.