Kefalonia Water Temperature
Updated Wed 00:06 (Europe/Athens)
Greece · Forecast updated Sep 23, 2026, 00:06 UTC
Current Sea Temperature
27.0°C
80.6°F
Warm water
Valid Sep 23, 2026, 00:06 (Europe/Athens). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
1.1°C above
The typical September average is 25.9°C (78.6°F) from the historical baseline.
Recent trend
Cooling by 1.1°C
Seven-day average: 27.7°C, versus 28.8°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 Kefalonia, typical monthly averages range from about 16.2°C (61.2°F) in February to 26.7°C (80.1°F) in August.
Over the past 30 days, the average sea temperature in Kefalonia has been 28.6°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Kefalonia, calculated from hourly observations for 2023–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 17.0–17.6°C | 17.3°C / 63.1°F |
| February | 15.7–16.8°C | 16.2°C / 61.2°F |
| March | 16.0–17.1°C | 16.7°C / 62.1°F |
| April | 16.2–17.9°C | 17.1°C / 62.8°F |
| May | 18.8–19.7°C | 19.4°C / 66.9°F |
| June | 23.2–24.1°C | 23.7°C / 74.7°F |
| July | 25.8–27.0°C | 26.2°C / 79.2°F |
| August | 25.7–28.5°C | 26.7°C / 80.1°F |
| September | 25.2–26.8°C | 25.9°C / 78.6°F |
| October | 22.4–24.5°C | 23.3°C / 73.9°F |
| November | 21.0–22.1°C | 21.6°C / 70.9°F |
| December | 18.1–18.9°C | 18.6°C / 65.5°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (38.21, 20.54). 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.
Kefalonia in January
Typical January water temperature near Kefalonia is 17.3°C (63.1°F), with yearly monthly means from 17.0–17.6°C.
Kefalonia in February
Typical February water temperature near Kefalonia is 16.2°C (61.2°F), with yearly monthly means from 15.7–16.8°C.
Kefalonia in March
Typical March water temperature near Kefalonia is 16.7°C (62.1°F), with yearly monthly means from 16.0–17.1°C.
Kefalonia in April
Typical April water temperature near Kefalonia is 17.1°C (62.8°F), with yearly monthly means from 16.2–17.9°C.
Kefalonia in May
Typical May water temperature near Kefalonia is 19.4°C (66.9°F), with yearly monthly means from 18.8–19.7°C.
Kefalonia in June
Typical June water temperature near Kefalonia is 23.7°C (74.7°F), with yearly monthly means from 23.2–24.1°C.
Kefalonia in July
Typical July water temperature near Kefalonia is 26.2°C (79.2°F), with yearly monthly means from 25.8–27.0°C.
Kefalonia in August
Typical August water temperature near Kefalonia is 26.7°C (80.1°F), with yearly monthly means from 25.7–28.5°C.
Kefalonia in September
Typical September water temperature near Kefalonia is 25.9°C (78.6°F), with yearly monthly means from 25.2–26.8°C.
Kefalonia in October
Typical October water temperature near Kefalonia is 23.3°C (73.9°F), with yearly monthly means from 22.4–24.5°C.
Kefalonia in November
Typical November water temperature near Kefalonia is 21.6°C (70.9°F), with yearly monthly means from 21.0–22.1°C.
Kefalonia in December
Typical December water temperature near Kefalonia is 18.6°C (65.5°F), with yearly monthly means from 18.1–18.9°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 | 21.1°C / 70.0°F | 24.4°C / 75.9°F | 27.5°C / 81.5°F |
| July | 25.4°C / 77.7°F | 26.8°C / 80.2°F | 28.8°C / 83.8°F |
| August | 27.0°C / 80.6°F | 28.1°C / 82.6°F | 29.7°C / 85.5°F |
| September | 26.4°C / 79.5°F | 28.3°C / 83.0°F | 29.6°C / 85.3°F |
Partial coverage: 4 calendar months with records. Profile calculated from 2745 hourly forecast records across 4 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Kefalonia
Ionian island with the turquoise water of Myrtos and sheltered pebble coves.
- Area
- Ionian Islands
Kefalonia Water Temperature: Common Questions
What is the water temperature in Kefalonia today?
The current sea surface temperature near Kefalonia is 27.0°C (80.6°F). Over the last 30 days, the average has been 28.6°C.
When is the water warmest in Kefalonia?
The water is typically warmest in August, at around 26.7°C (80.1°F) in the 2023–2025 historical baseline.
When is the water coldest in Kefalonia?
The water is typically coldest in February, at around 16.2°C (61.2°F) in the same historical baseline. A wetsuit is usually recommended during this period.
Can you swim in Kefalonia today?
At 27.0°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 Kefalonia.
View Snorkel Forecast →