Sea temperature in Poland

The sea in Poland peaks in August, when the water averages around 19°C.

On average, 0 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.

Outside peak season the water drops toward 7°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.

The coldest month is typically February at around 2°C, when cold-water swimmers dominate the coast.

Long-term climatology for Poland shows an annual mean sea temperature of 10°C, ranging from 2°C in winter to 19°C at the summer peak.

The seasonal swing is roughly 17°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.

Recent decades have trended slightly warmer at Poland, in line with regional sea-surface temperature records for the wider basin.

Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.