Kos Water Temperature
Updated Wed 04:51 (Europe/Athens)
Greece · Forecast updated Sep 23, 2026, 04:51 UTC
Current Sea Temperature
26.8°C
80.2°F
Warm water
Valid Sep 23, 2026, 04:51 (Europe/Athens). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
0.4°C above
The typical September average is 26.4°C (79.5°F) from the historical baseline.
Recent trend
Cooling by 0.9°C
Seven-day average: 26.7°C, versus 27.6°C in the prior seven days.
What to wear
Warm water
Most people are comfortable in swimwear or a light rash guard.
Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions or replace the snorkel forecast.
Typical Sea Temperature Over the Year
In the historical baseline for Kos, typical monthly averages range from about 17.6°C (63.7°F) in March to 27.0°C (80.6°F) in August.
Over the past 30 days, the average sea temperature in Kos has been 27.2°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Kos, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 18.7–20.3°C | 19.4°C / 66.9°F |
| February | 17.4–18.7°C | 18.1°C / 64.6°F |
| March | 16.9–18.2°C | 17.6°C / 63.7°F |
| April | 17.5–18.9°C | 18.1°C / 64.6°F |
| May | 19.2–20.3°C | 19.7°C / 67.5°F |
| June | 22.2–23.9°C | 22.9°C / 73.2°F |
| July | 24.2–26.4°C | 25.6°C / 78.1°F |
| August | 26.6–27.1°C | 27.0°C / 80.6°F |
| September | 25.8–27.1°C | 26.4°C / 79.5°F |
| October | 23.9–25.4°C | 24.5°C / 76.1°F |
| November | 21.9–23.0°C | 22.5°C / 72.5°F |
| December | 19.9–21.2°C | 20.7°C / 69.3°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (36.88, 27.29). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
Water temperature by month
Each month uses the 2023–2025 baseline. The range is the lowest and highest yearly monthly mean, not an hourly extreme.
Kos in January
Typical January water temperature near Kos is 19.4°C (66.9°F), with yearly monthly means from 18.7–20.3°C.
Kos in February
Typical February water temperature near Kos is 18.1°C (64.6°F), with yearly monthly means from 17.4–18.7°C.
Kos in March
Typical March water temperature near Kos is 17.6°C (63.7°F), with yearly monthly means from 16.9–18.2°C.
Kos in April
Typical April water temperature near Kos is 18.1°C (64.6°F), with yearly monthly means from 17.5–18.9°C.
Kos in May
Typical May water temperature near Kos is 19.7°C (67.5°F), with yearly monthly means from 19.2–20.3°C.
Kos in June
Typical June water temperature near Kos is 22.9°C (73.2°F), with yearly monthly means from 22.2–23.9°C.
Kos in July
Typical July water temperature near Kos is 25.6°C (78.1°F), with yearly monthly means from 24.2–26.4°C.
Kos in August
Typical August water temperature near Kos is 27.0°C (80.6°F), with yearly monthly means from 26.6–27.1°C.
Kos in September
Typical September water temperature near Kos is 26.4°C (79.5°F), with yearly monthly means from 25.8–27.1°C.
Kos in October
Typical October water temperature near Kos is 24.5°C (76.1°F), with yearly monthly means from 23.9–25.4°C.
Kos in November
Typical November water temperature near Kos is 22.5°C (72.5°F), with yearly monthly means from 21.9–23.0°C.
Kos in December
Typical December water temperature near Kos is 20.7°C (69.3°F), with yearly monthly means from 19.9–21.2°C.
Forecast archive (growing)
These values come from hourly forecasts SnorkelForecast has stored. They cover only months with records and do not replace the historical baseline.
| Month | Min | Average | Max |
|---|---|---|---|
| June | 21.6°C / 70.9°F | 23.8°C / 74.9°F | 26.7°C / 80.1°F |
| July | 23.9°C / 75.0°F | 24.9°C / 76.8°F | 27.5°C / 81.5°F |
| August | 25.2°C / 77.4°F | 27.3°C / 81.2°F | 28.8°C / 83.8°F |
| September | 25.7°C / 78.3°F | 27.1°C / 80.9°F | 28.7°C / 83.7°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2748 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Kos
Dodecanese island with calm bays and clear shallows along long beaches.
- Area
- Dodecanese
Kos Water Temperature: Common Questions
What is the water temperature in Kos today?
The current sea surface temperature near Kos is 26.8°C (80.2°F). Over the last 30 days, the average has been 27.2°C.
When is the water warmest in Kos?
The water is typically warmest in August, at around 27.0°C (80.6°F) in the 2023–2025 historical baseline.
When is the water coldest in Kos?
The water is typically coldest in March, at around 17.6°C (63.7°F) in the same historical baseline. A wetsuit is usually recommended during this period.
Can you swim in Kos today?
At 26.8°C, the water is usually comfortable for swimming and snorkeling.
Full Snorkeling Forecast
See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Kos.
View Snorkel Forecast →