Weather in Kefalonia in December

How December compares

December is the 10th warmest month of the year in Kefalonia and ranks 83rd of 134 destinations we compare for December - see where else is hot in December. Within Greece it is 21st of 44 (Greece in December). Against London's average high of 7.7°C in December, Kefalonia is 7.2°C warmer by day and 9.6°C warmer at night.

Daytime and night-time in December

The typical December day in Kefalonia peaks at 14.9°C, but that is an average: the warmest 10% of days reach 17.7°C or more. Days over 25°C are rare. Nights average 12.3°C; one night in ten drops to 8.8°C or lower, so pack a layer for evenings - it is genuinely cool after dark. Between 1991 and 2020 the hottest December day here reached 21.5°C (2010-12-03) and the coldest night 3.1°C (2001-12-18).

Rain in December

Wet (more than 8 rainy days): about 13 days with 1 mm or more, 156 mm in total. Year to year it varies a lot - the wettest December was 2002 with 391 mm, the driest 2015 with 11 mm. Humidity averages 71%.

Sea temperature in December

The sea averages 17.7°C - too cold for most (under 18°c). Depending on the year it ranges from 16.7°C to 18.7°C. For the warmest sea here, come in August (26.0°C).

Sunshine and daylight

Around 4.3 hours of sunshine a day (estimated from cloud cover), 9.4 hours of daylight: the sun rises about 07:47 and sets about 17:19 local time in mid-December. Average cloud cover is 54%.

Is December a good time to visit Kefalonia?

December is not the strongest month here: cool days and frequent rain. The best months for Kefalonia on our scoring are July, August, June; months averaging 25°C or more: Jul, Aug, Sep.

Mild afternoons, but pack for cooler spells

The average daytime high of 14.9°C is comfortable for being outdoors in layers, rather than sitting around in summer clothes. Average night lows of 12.3°C mean you will still want a jacket for evenings. There is some variation behind those averages: the warmest days reach around 18°C or more, while the coldest nights can fall to around 9°C or below. Pack trousers, light jumpers and a warmer outer layer instead of relying on a mild forecast. Midday is a sensible time to make the most of any warmth, but this is not a month to plan around sunbathing.

Rain is the main compromise

December is wet, with about 13 days recording rain and 156.0 mm falling across the month on average. That does not mean every wet day is a complete write-off, but it does make a fixed outdoor schedule a poor fit. A waterproof jacket and shoes that cope with rain are sensible essentials. There are about 9.4 hours of daylight, with 4.3 hours of sunshine on average, so keep outdoor plans within the daylight window and take advantage of clear spells. This month suits travellers who can change plans without feeling that a rainy afternoon has spoiled the trip.

The sea is cold, not a winter swimming draw

At an average of 17.7°C, the sea is cold for holiday swimming. Its December range of 17°C to 19°C means some years are less chilly than others, but even the warmer end remains below the 22°C swimming benchmark. If comfortable dips are central to your holiday, December is a poor choice. Treat time by the water as an outdoor outing in suitable clothing rather than a beach day. The balance is clearer if you separate mild air from warm water: a pleasant afternoon does not make the sea comfortable, and sunshine alone is not a good reason to pack mainly beachwear.