INSTRUMENT / SEA TEMPERATURE
Kefalonia Water Temperature
Updated Sat 14:57 (Europe/Athens)
Greece · Forecast updated Nov 7, 2026, 14:57 UTC
Current Sea Temperature
21.7°C
71.1°F
Cool water
Valid Nov 7, 2026, 14:57 (Europe/Athens). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
Close to average
The typical November average is 21.6°C (70.9°F) from the historical baseline.
Recent trend
Cooling by 1.0°C
Seven-day average: 22.1°C, versus 23.1°C in the prior seven days.
What to wear
Cool water
A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
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 23.3°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 2022–2025. 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 2022–2025 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.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: December 18.6°C · February 16.2°C.
Explore Kefalonia sea temperature in January, including swim comfort and month comparisons →
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.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: January 17.3°C · March 16.7°C.
Explore Kefalonia sea temperature in February, including swim comfort and month comparisons →
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.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: February 16.2°C · April 17.1°C.
Explore Kefalonia sea temperature in March, including swim comfort and month comparisons →
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.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: March 16.7°C · May 19.4°C.
Explore Kefalonia sea temperature in April, including swim comfort and month comparisons →
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.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: April 17.1°C · June 23.7°C.
Explore Kefalonia sea temperature in May, including swim comfort and month comparisons →
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.
Swimming and snorkeling: mild water. A rash guard is useful; cold-sensitive snorkelers may prefer a shorty wetsuit.
Adjacent months: May 19.4°C · July 26.2°C.
Explore Kefalonia sea temperature in June, including swim comfort and month comparisons →
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.
Swimming and snorkeling: warm water. Most people are comfortable in swimwear or a light rash guard.
Adjacent months: June 23.7°C · August 26.7°C.
Explore Kefalonia sea temperature in July, including swim comfort and month comparisons →
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.
Swimming and snorkeling: warm water. Most people are comfortable in swimwear or a light rash guard.
Adjacent months: July 26.2°C · September 25.9°C.
Explore Kefalonia sea temperature in August, including swim comfort and month comparisons →
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.
Swimming and snorkeling: warm water. Most people are comfortable in swimwear or a light rash guard.
Adjacent months: August 26.7°C · October 23.3°C.
Explore Kefalonia sea temperature in September, including swim comfort and month comparisons →
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.
Swimming and snorkeling: mild water. A rash guard is useful; cold-sensitive snorkelers may prefer a shorty wetsuit.
Adjacent months: September 25.9°C · November 21.6°C.
Explore Kefalonia sea temperature in October, including swim comfort and month comparisons →
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.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: October 23.3°C · December 18.6°C.
Explore Kefalonia sea temperature in November, including swim comfort and month comparisons →
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.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: November 21.6°C · January 17.3°C.
Explore Kefalonia sea temperature in December, including swim comfort and month comparisons →
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 | 25.7°C / 78.3°F | 28.0°C / 82.3°F | 29.6°C / 85.3°F |
| October | 22.8°C / 73.0°F | 24.0°C / 75.3°F | 25.7°C / 78.3°F |
| November | 21.3°C / 70.3°F | 21.9°C / 71.4°F | 22.8°C / 73.0°F |
Partial coverage: 6 calendar months with records. Profile calculated from 3839 hourly forecast records across 6 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 21.7°C (71.1°F). Over the last 30 days, the average has been 23.3°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 2022–2025 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 21.7°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 →