The hottest month in Kefalonia is August when the average maximum temperature is 31°, average temperature is 26° and average minimum temperature is 22°.
The coolest month in Kefalonia is February when the average maximum temperature is 15°, average temperature is 12° and average minimum temperature is 9°.
The longest days in Kefalonia are in June, with an average of 14.8 hours of daylight per day. December has the shortest days with an average of 9.5 hours of daylight per day.
The sunniest days in Kefalonia are in July which has the most hours of sunshine per day with an average of 11.9 hours of sunshine per day, making it a very sunny and pleasant month with long bright days. December has the least sunshine with an average of 4.4 hours of sunshine per day, making it a sunny month that is overcast at times.
The ultraviolet index is the highest in July when it reaches 10.4 and lowest in December when it reaches 2.1.
An ultraviolet index reading of 8 to 10 indicates a very high risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 15 minutes. Take extra precautions because unprotected skin and eyes will be damaged and can burn quickly. Tanning will be safest before 10am and after 4pm but only with a good application of sun screen. For those with sensitive skin stay in the shade and wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days. Watch out for relections from water that may increase ultraviolet exposure.
The warmest sea water temperatures in Kefalonia are found in August when they peak at 25° and lowest in March when they dip to 15°.
The sea is best for swimming between June and December when the temperature is above 19° which is comfortable for swimming though some may prefer warmer water.
The wettest month in Kefalonia is December with 17.4cm of rain and February has the most days of rain with 11.5 days with some rain, a slightly wet time to visit the beach.
The driest month in Kefalonia is June with 0.7cm of rain and July has the fewest days of rain with 1.3 days with some rain, an extremely dry time to visit the beach.
The most humid month in Kefalonia is August with a dew point (an indicator of humidity) of 23° which is very humid and quite uncomfortable for most unless you are on a beach. At night you would most likely require a fan.
The least humid month in Kefalonia is January with a dew point of 9° which is a bit dry for some.
The most windy month in Kefalonia is February when the average maximum windspeed is 24kmh and the average wind speed is 13kmh.
The least windy month in Kefalonia is October when the average maximum windspeed is 20kmh and the average wind speed is 9kmh.