The island of Kefalonia enjoys a typical Mediterranean climate, which is why it is wonderful in the months of May to October, during which temperatures vary from 23° in the early summer months to over 30° in the hottest months of July and August. Characteristic of the island is the presence of light winds that, on some days, cool the air during the hottest months of the summer. From October onwards, the coldest days of winter on the island begin. It is always rainy and mild, with clear days and sea breezes alternating with rainy days.

Kefalonia is the ideal island for summer holidays, but not only! If your biggest doubt is choosing the best time to go to Kefalonia, its pleasant and generally warm climate will make your choice easy.
The ideal time to visit the island is definitely between May and October. Particularly during the summer months, from the end of May to the last days of September, the island gives the best of its Mediterranean climate, with temperatures reaching 30° and peaking during the hottest days of August, always mitigated by a sea breeze that makes tourism pleasant. During the month of August, most of the influx of tourists is concentrated, so the small towns become populated with bars, restaurants and clubs, shops and small taverns that attract visitors both during the day and for wonderful summer evenings.
During the spring, however, in March, April and May, the island offers a mild climate with little rain, ideal for relaxing tourism on the quiet, still uncrowded beaches. Thanks to the sea breeze typical of Kefalonia, there are warm days and cool evenings, ideal for walks and excursions inland.
Many tourists choose to visit the island during the autumn months, from September to November, during which the climate still allows for sunny days on the beach, in the quiet of an almost deserted island.
The hottest months of the year in Kefalonia are June, September, July and August, when the monthly average temperature reaches 29 °C, while the coldest months of March, January and February the thermometer drops up to 5 °C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Max °C | 12 | 12 | 14 | 17 | 22 | 26 | 29 | 29 | 26 | 21 | 17 | 13 |
| Min °C | 5 | 5 | 6 | 9 | 12 | 16 | 18 | 18 | 16 | 13 | 9 | 7 |
In Kefalonia rainiest months of the year are November and December during which monthly rainfall average reaches 115 mm. On the other side, driest months are June, August and July when the average rainfall is reduced to 0 mm per month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| mm | 80 | 55 | 45 | 30 | 20 | 5 | 0 | 5 | 30 | 70 | 100 | 115 |
| Days | 12 | 11 | 10 | 10 | 7 | 5 | 3 | 4 | 5 | 8 | 10 | 12 |
June, August and July are sunniest months of the year. During that months, from sunrise to sunset there are 14 total sunshine hours in Kefalonia. In February, November, January and December sunshine hours are reduced to 6.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hours | 6 | 7 | 8 | 10 | 12 | 13 | 14 | 13 | 10 | 8 | 7 | 6 |
Months of the year when sea water is warmer are July, September and August, average temperature is around 26 °C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| °C | 16 | 15 | 15 | 16 | 19 | 23 | 25 | 26 | 25 | 23 | 20 | 17 |