Kefalonia weather by month

When to go to Kefalonia

For beach weather, look at months where the daytime average clears 25°C and rainy days stay low: July, August, September. December is the wettest month (156 mm, about 13 rainy days) and July the driest (5 mm). The sea is warmest in August at 26.0°C and coolest in March at 15.1°C.

Getting there

A direct flight from London Gatwick to Kefallinia Airport (EFL, 7 km from Argostólion) takes roughly 3 h 30 min - short-haul (up to 4.5 h) by UK standards. Time-zone: Europe/Athens.

Records and extremes, 1991-2020

The hottest day recorded in Kefalonia between 1991 and 2020 reached 37.0°C on 1 July 2017; the coldest fell to -0.4°C on 13 February 2004. In August one day in ten tops 29.9°C and about 10% of days pass 30°C; in February one night in ten drops to 7.1°C or below. The wettest single month of the period was December 2002 with 391 mm, against a December average of 156 mm.

Winter and spring: mild days, cool water

December, January and February suit travellers who do not need reliable beach weather. February is coolest, with days around 13°C, while December averages 13 rain days, so bring a waterproof and keep outdoor plans flexible. January is only slightly warmer than February; layers remain useful after dark. March lifts daytime temperatures to 15°C, but the sea stays cool and showers remain a consideration. April is a clearer step towards outdoor holiday weather, with 8 hours of sunshine and fewer wet days, although swimming will still feel chilly. May offers the best spring balance: days average 21°C and rain becomes less frequent. Pack light clothes for daytime, a layer for evenings and realistic expectations for a sea averaging 19°C.

Summer: the strongest choice for sunshine and swimming

June is a good fit if you want summer warmth without choosing the hottest month. Days average 25°C, the sea reaches 22°C and rain is infrequent, making it easier to plan time outdoors. July has the most sunshine, averaging 14 hours daily, and warmer water for swimming. August is hottest, with daytime averages of 28°C and the sea at 26°C. Both July and August average just 1 rain day, although that does not guarantee a completely dry stay. Choose lightweight clothing, use sun protection and leave room for shade around midday. Nights average 24°C in both months, so evenings offer less of a cool-down than in June.

Autumn: warm water, but increasingly changeable weather

September is the strongest autumn option for a swimming holiday: both daytime air and sea temperatures average 25°C. The catch is rain, with 6 wet days compared with summer's much drier pattern, so leave some flexibility rather than assuming every day will suit the beach. October stays mild at 22°C by day, and its 23°C sea is warmer than June's, but shorter sunshine hours and more rain make it a less dependable beach choice. November shifts further towards a mild-weather break rather than a sun-focused trip. Days average 18°C, with 12 rain days, so a waterproof and layers become more useful than an itinerary built around swimming.