Kefalonia weather in August

August in Kefalonia: sweltering, dry, with muggy air — fine if you can take 37°C afternoons.

Updated September 2026 · climate normals from ERA5 reanalysis

Kefalonia🇬🇷 Greece · Greece & Cyprus · Island91
  1. 54Jan
  2. 65Feb
  3. 72Mar
  4. 78Apr
  5. 83May
  6. 92Jun
  7. 93Jul
  8. 91Aug
  9. 87Sep
  10. 79Oct
  11. 61Nov
  12. 56Dec

#3 of 12 months in Kefalonia · #182 of 1413 destinations to visit in August · comfort 91/100 (tier S)

Days
32°C
Nights
23°C
Wet days
2
Sun
12.5 h
Humidity
76%
Daylight
14 h
Kefalonia, Greece
Photo: Valentina Nicola · Pexels

Traveller notes on Kefalonia in August

Kefalonia's forum puts August around 30°C in the shade with roughly 12 hours of sunshine a day, capable of hitting 40°C on the hottest days especially early in the month. Regulars describe the classic siesta rhythm — sightseeing before 11:30am, shade and a long lunch through the peak heat, back out around 4pm — and note the Greek heat feels notably less oppressive than a 30°C day in a humid climate.
Tripadvisor community · August · 1 month ago · Read more on Tripadvisor ↗

Other months in Kefalonia

Regulars are honest this month comes down to luck - some visitors get genuinely good weather throughout, others hit a rainy, changeable stretch, the rain itself typically warm rather than a cold soak. Our row backs that mild, genuinely wet read, 24.8C reading as a hot 25C, over 17.3C nights feeling 16C, with a substantial 107.1mm of rain across 8.3 days and a real 26.9 kph wind. Regulars are consistent by mid-to-late month most smaller resorts have shut down for the season, Argostoli and Lixouri the recommended base since they stay open and genuinely lively regardless. The sea sits at a warm, swimmable 24.6C, right at the lower edge of comfortable for most swimmers. The record: 9.4 hours of sun and AQI 50.
ComesDownToLuckArgostoliStaysOpen · October · 1 month ago · Read more on Tripadvisor ↗
Regulars describe the sea here with a level of detail worth keeping: by late May the top metre or so has warmed while it stays noticeably colder just beneath, swimmable rather than comfortable for lingering. Our column reads 18.7C, and regulars specifically recommend June instead if the sea and settled weather matter more than avoiding crowds, since June's water is warmer even if only marginally so early in the month. Our row for May gives 23.9C reading as 25C over 15.9C nights, with 24.1mm of rain across 4.4 days - changeable early in the month, improving as it goes. The island stays genuinely quiet through May, busier but not excessively so once June arrives. The record: humidity 80 percent, 12.2 hours of sun, a 24.8 kph wind and AQI 55.
WarmOnTopChillyABitDeeper · May · 1 month ago · Read more on Tripadvisor ↗
Regulars describe September as hot by day, sometimes cool and changeable in the first week and then settled, with any rain arriving warm. Our row gives 28.6C reading as 32C over 20.6C nights, and 64.3mm across only 4.9 days, so the wet part is brief. The sea, they say, is at its warmest now - 25.2C on our reading, level with the air's daily mean. The crowds of July and August have gone while everything stays open, with one caveat worth knowing: as the season winds down the resorts quieten and menus can narrow, because stocks are run down rather than replaced. The main villages are still working in late September. The record: humidity 72 percent, 10.8 hours of sun and a 25.2 kph wind.
TheMenusGetShorter · September · 1 month ago · Read more on Tripadvisor ↗
June on Kefalonia is good and, by regulars' own accounts, unpredictable: some describe 28C days with 17 or 18C evenings, others 30 to 36C and nights that never turn chilly. Our row's 29.3C over 20.3C sits between the two, reading as 33C, with 15.1mm across 1.7 precipitation days and 13.3 hours of sun. Early June still has low visitor numbers, with the main towns busier but not oppressive, and everything is in flower and green before the summer burns it off. The island's famous beach comes with a condition: Myrtos is very exposed to wind and weather, so the postcard version needs a still day - our 22.4 kph is the average it has to beat. The record: humidity 81 percent, a 23.1C sea and AQI 57.
MyrtosNeedsAStillDay · June · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Kefalonia's card on the map.

Kefalonia climate normals — August

Daytime high32°C / 90°F🔥 sweltering
Nighttime low23°C / 74°F
Feels like (high)37°C / 99°F
Sea temperature26°C / 79°F😎 warm sea
Rainfall7 mm / 0.3 in☀️ dry
Rainy days2 days
Humidity76%💦 very humid
Dew point21°C / 70°F
Sunshine12.5 h/day
Daylight13.6 h
Wind24 km/h / 15 mph
Air quality (US AQI)62🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Kefalonia in August

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Peak crowdsAugust peak, Summer holidays in Greece, school holidays in 7 of the markets that fill it(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Kefalonia's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Best weatherKefalonia's weather peaks June–August, best around July.

August includes Loggerhead turtles.

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Best weatherFair weatherToughest weather

What's on in Kefalonia in August

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Nature

    Loggerhead turtles

    1 May – 15 Sep · usuallyTurtle nesting

    Loggerheads nest on the south-coast beaches around Katelios through the summer, and adults hang around the fishing boats in Argostoli harbour waiting for scraps.

  • Season

    Sea warm enough to swim

    1 Jun – 15 Oct · usually

    The Ionian is calmer and clearer than the Aegean because the meltemi does not reach here. Myrtos is the postcard; the small coves on the Paliki side are the swim.

  • Hazard

    Wildfire season

    15 Jun – 30 SepSmoke season

    The fir forest on Mount Ainos and the scrub above the coast road carry real risk in a dry summer, and the national park closes to visitors on high-risk days. Source ↗

  • Holiday

    August peak

    1–31 AugSchool holidaysCrowdedBook early

    Greek holidays and the Dormition on 15 August fill the island at once, and the ferries from Kyllini and Patras are the choke point. Hire cars go before rooms do. Source ↗

  • Festival

    Snakes of the Virgin, Markopoulo

    6–16 AugReligious feast

    Small harmless cat snakes turn up in the church at Markopoulo in the days before 15 August and are handled by the congregation. Villagers read a year with no snakes as a bad sign. Source ↗

  • Nature

    Robola harvest

    20 Aug – 30 Sep · usually

    The vines grow on limestone rubble on the slopes below Ainos and are picked from late August. The cooperative at Omala opens for tasting through the harvest.

What's on around the world in August →

Nearby, and something's on

Within 300 km of Kefalonia — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Kefalonia?

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Kefalonia in August — FAQ

Is August a good time to visit Kefalonia?
August in Kefalonia: sweltering, dry, with muggy air — fine if you can take 37°C afternoons. It ranks #3 of 12 months for Kefalonia on SeasonMap's comfort score (91/100).
What is the weather like in Kefalonia in August?
In August, Kefalonia averages a daily high of 32.1°C and a low of 23.3°C, with about 6.5 mm of rain over roughly 1.5 rainy days.
What is the air quality in Kefalonia in August?
Kefalonia has a mean US Air Quality Index of about 62 in August.

Within 300 km: Zakynthos' Loggerhead nesting in Laganas Bay on 1 May – 31 Oct, and Corfu's Cricket on the Spianada around 1 May – 15 Sep.