Greece
Kos · Aegean Sea

Marmari BeachSea temperature now

Greek beach near Marmari.

Warm water with a light chop and a light breeze — great swimming conditions.

Sea temperature now
24.6°Chot
Excellent
Updated just now · Source: Open-Meteo Marine
Air
Waves
Wind
UV

Location

Marmari Beach on the map, with nearby beaches and live sea temperatures.

7-day forecast

Water, air, waves, wind and UV outlook for the week ahead.

Monthly sea temperature averages

Typical year-round water temperature, based on regional climatology.

15°C26°C· Current month outlined· “Best” = within 2°C of the annual peak

Best time to swim in Marmari Beach

The sea in Marmari Beach peaks in August, when the water averages around 26°C.

The main swimming season runs from May – November, when surface temperatures stay comfortable for extended sessions.

On average, 7 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.

Shoulder months like April and December are noticeably cooler but often quieter, with fewer crowds and steadier weather.

Outside peak season the water drops toward 17°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.

The coldest month is typically February at around 15°C, when cold-water swimmers dominate the coast.

Marmari Beach sea temperature history

Long-term climatology for Marmari Beach shows an annual mean sea temperature of 20°C, ranging from 15°C in winter to 26°C at the summer peak.

The seasonal swing is roughly 11°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 Marmari Beach, 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.

Jan
16°C
Feb
15°C
Mar
15°C
Apr
17°C
May
20°C
Jun
23°C
Jul
25°C
Aug
26°C
Sep
25°C
Oct
22°C
Nov
20°C
Dec
17°C

Marmari Beach sea temperature: frequently asked questions

What is the warmest month to swim in Marmari Beach?

August is the warmest month in Marmari Beach, when the sea averages about 26°C. Late-season warmth often persists a few weeks after peak.

When is the sea coldest in Marmari Beach?

The coldest month in Marmari Beach is typically February, when the water averages around 15°C. Cold-water swimmers and surfers dominate this period.

When can you swim in Marmari Beach without a wetsuit?

The main swimming season in Marmari Beach runs from May – November — about 7 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.

Do I need a wetsuit in Marmari Beach?

Outside peak summer the water in Marmari Beach drops toward 17°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.

What is the average sea temperature in Marmari Beach?

The long-term annual mean sea temperature in Marmari Beach is about 20°C, based on multi-decadal climatology of the surrounding waters.

How do I check the current sea temperature in Marmari Beach?

The live reading at the top of this page shows the current sea temperature in Marmari Beach, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.

Year-round sea temperature

Best swim months: May – Jun – Jul – Aug – Sep – Oct – Nov

MonthSeaComfort
Jan16°CBracing
Feb15°CBracing
Mar15°CBracing
Apr17°CBracing
May20°CPleasant
Jun23°CWarm
Jul25°CWarm
Aug26°CHot
Sep25°CWarm
Oct22°CWarm
Nov20°CPleasant
Dec17°CBracing

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