Baltic Sea temperatures on September 15th: Is swimming still an option?

Baltic Sea temperatures on September 15th: Is swimming still an option?

On September 15, 2025, water temperatures on the Baltic Sea coast in Mecklenburg-Western Pomerania are a hot topic. For many holidaymakers and locals, jumping into the water is a refreshing change, especially on warm days. Swimming in the Baltic Sea is a tradition here, both in summer and winter. The water temperature plays a crucial role. An interactive map currently shows the temperatures at 22 popular bathing spots, which are recorded and updated daily by the Federal Maritime and Hydrographic Agency (BSH) and the German Weather Service (DWD).

Holiday resorts like Warnemünde, Kühlungsborn and Binz are very popular when it comes to refreshing yourself in the water on hot days. The data collected provides forecasts for five different times: 8 a.m., 11 a.m., 2 p.m., 5 p.m. and 8 p.m., and measures temperatures at well-known water gauge stations such as Boltenhagen, Heringsdorf and Graal-Müritz. These daily updates help beachgoers choose the optimal time to swim.

Water temperatures and climate change

Last year the North and Baltic Seas experienced above-average warmth. This reports World, where the average temperature of the German Baltic Sea was 9.6 degrees in 2024, which is more than one degree above the long-term average. This made 2024 the second warmest year for the Baltic Sea since records began, only 2020 was warmer. The North Sea also had an average temperature of 11.1 degrees above the long-term average from 1997 to 2021.

These developments can be directly attributed to advancing climate change. A report from Mirror finds that the heat wave in the oceans not only affects temperatures but also increases regional differences. While high values ​​are measured in the Baltics, the water temperatures off the Swedish east coast tend to be lower.

A look into the future

With continuous warming, which has reached almost 1.5 degrees in the North Sea since 1969 and even 1.9 degrees in the Baltic Sea since 1990, the need to treat our waters sensitively is becoming even more urgent. The constantly rising temperatures pose challenges not only to the aquatic flora and fauna, but also to people who want to relax on the beaches.

It is therefore worth regularly taking a look at the latest measurements and forecasts, especially when it comes to enjoying the cool water. The Baltic Sea remains a popular destination – no matter what the weather. And perhaps you will soon have the opportunity to do a few laps in the sea in pleasant water temperatures before autumn arrives.