Weather in Kefalonia in August

How August compares

August is the 1st warmest month of the year in Kefalonia and ranks 82nd of 134 destinations we compare for August - see where else is hot in August. Within Greece it is 27th of 44 (Greece in August). Against London's average high of 21.4°C in August, Kefalonia is 6.6°C warmer by day and 11.0°C warmer at night.

Daytime and night-time in August

The typical August day in Kefalonia peaks at 28.0°C, but that is an average: the warmest 10% of days reach 29.9°C or more. About 99% of days top 25°C and 1 in 10 pass 30°C. Nights average 24.5°C; one night in ten drops to 23.0°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest August day here reached 35.4°C (2017-08-09) and the coldest night 19.4°C (1991-08-30).

Rain in August

Dry (3 rainy days or fewer): about 1 days with 1 mm or more, 7 mm in total. Year to year it varies a lot - the wettest August was 1995 with 55 mm, the driest 1993 with 0 mm. Humidity averages 77%, which makes the heat feel heavier than the thermometer suggests.

Sea temperature in August

The sea averages 26.0°C - warm enough to swim (22°c+). Depending on the year it ranges from 24.8°C to 27.0°C. This is the warmest the sea gets here all year.

Sunshine and daylight

Around 12.4 hours of sunshine a day (estimated from cloud cover), 13.5 hours of daylight: the sun rises about 06:53 and sets about 20:32 local time in mid-August. Average cloud cover is 8%.

Is August a good time to visit Kefalonia?

Yes - it is one of the better months: hot days, little rain and long sunny days. The best months for Kefalonia on our scoring are July, August, June; months averaging 25°C or more: Jul, Aug, Sep.

Plan around the heat, including after dark

August is Kefalonia's warmest month, but the typical daytime high is not the whole story. Around 10% of days reach 30°C, so leave room to slow down when it feels hotter than expected. Put longer walks in the morning, keep midday plans flexible and choose shade for breaks. Humidity averages 77%, which can make the warmth feel close rather than crisp. Evenings offer limited relief: light, loose clothing is more useful than heavy layers, and air conditioning is a sensible accommodation priority if you struggle to sleep in warmth. This is a better fit for travellers happy to adjust their pace than for anyone who needs reliably cool afternoons.

Warm swimming weather with little rain

The sea is a strong reason to choose August. Its average temperature makes swimming a comfortable prospect, with the year-to-year range of 25°C to 27°C keeping it firmly on the warm side. There is plenty of time outdoors too, with about 12.4 hours of sunshine a day. Bring sun protection and plan access to shade rather than treating all that sunshine as time to spend exposed. Rain is usually a minor interruption, with around 1 day recording at least 1 mm during the month. That makes weather-dependent plans a reasonable bet, though dry averages are not a promise of an entirely rain-free stay. Prioritise light clothing and swimwear, with a light rain layer as a precaution.