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Baltic Sea water temperature

Baltic Sea, Kappeln · Sea/Coast

The current water temperature at Baltic Sea is 16.9 °C (as of September 20, 2026, source: Open-Meteo marine model).

The sea lags the air by weeks: the warmest water often arrives after the warmest days. Measured buoy values show this honestly.

16.9 °C
Measured: September 20, 2026 · continuously updated
💧 Water 16.9° · ☀️ Air 16.2°
Temperature trend of recent weeks
Baltic Sea
Photo: wusel007 · CC BY-SA 3.0 · Wikimedia Commons

Measurement series & statistics

This measurement series includes 610 data points since July 22, 2026.

Lowest recorded value: 16.9 °C on September 19, 2026 · highest value: 20.4 °C on August 5, 2026.

In September, temperatures have ranged between 16.9 °C and 18.9 °C.

The current value is 1.0 °C below the September average of this series.

Nearby waters

More measuring points: Baltic Sea

Frequently asked questions

Can you swim at Baltic Sea right now?
The current water temperature is 16.9 °C. See live swimming conditions, weather and quality in the BrrChecker app.

How warm is the water at Baltic Sea?
Currently 16.9 °C (updated continuously).

How warm is at Baltic Sea in September?
In September, the water temperature recently averaged 17.9 °C.

When is the water warmest at Baltic Sea?
Across the measurement record, August is on average the warmest month (19.5 °C).

Open in the BrrChecker app

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