Where is the sea warmest in the Baltic in December?
In December the warmest sea in the Baltic is at Rønne, Denmark, at 7.0°C. Nowhere in the region is comfortable for swimming this month — not one of the 90 cities measured reaches 19.0°C.
| # | City | Country | Sea | Swimming |
|---|---|---|---|---|
| 1 | Rønne | Denmark | 7.0°C | Dangerous |
| 2 | Palanga | Lithuania | 6.9°C | Dangerous |
| 3 | Svetlogorsk | Russia | 6.9°C | Dangerous |
| 4 | Gdynia | Poland | 6.9°C | Dangerous |
| 5 | Kragerø | Norway | 6.9°C | Dangerous |
| 6 | Koszalin | Poland | 6.8°C | Dangerous |
| 7 | Gdańsk | Poland | 6.8°C | Dangerous |
| 8 | Reda | Poland | 6.8°C | Dangerous |
| 9 | Władysławowo | Poland | 6.8°C | Dangerous |
| 10 | Liepāja | Latvia | 6.8°C | Dangerous |
| 11 | Zelenogradsk | Russia | 6.7°C | Dangerous |
| 12 | Ventspils | Latvia | 6.7°C | Dangerous |
| 13 | Darłowo | Poland | 6.7°C | Dangerous |
| 14 | Ustka | Poland | 6.6°C | Dangerous |
| 15 | Frederikshavn | Denmark | 6.4°C | Dangerous |
| 16 | Faaborg | Denmark | 6.4°C | Dangerous |
| 17 | Ribnitz-Damgarten | Germany | 6.4°C | Dangerous |
| 18 | Sønderborg | Denmark | 6.3°C | Dangerous |
| 19 | Oldenburg in Holstein | Germany | 6.3°C | Dangerous |
| 20 | Kołobrzeg | Poland | 6.3°C | Dangerous |
| 21 | Trzebiatów | Poland | 6.3°C | Dangerous |
| 22 | Sandefjord | Norway | 6.3°C | Dangerous |
| 23 | Tønsberg | Norway | 6.3°C | Dangerous |
| 24 | Fehmarn | Germany | 6.3°C | Dangerous |
| 25 | Kappeln | Germany | 6.3°C | Dangerous |
Ranked on the NOAA OISST monthly climatology — a long-run average for December, not a forecast. A given December will run warmer or cooler than this, and the sea is warmest late in the afternoon and late in the season.