Corfu climate is generally mild and humid, with plenty of rain and mostly south or southeast winds.
Winters are mild with cooler season the first 20 days in January where temperatures approach zero but rarely fall below it.
The snow except from the top of Mount Pantocrator is unknown, it has snowed in the lowlands only around 3 times in the last 50 years.
During the winter winds are generally southeasterly and rains can hold for many days, the coldest days when winds are north or northeast, not exceed 10 to 15 per year and they are usually in January, without prejudice to other months.
These days temperature can fall really low, in Corfu north winds accompanied almost always with sunshine so it can not snow, humidity almost disappears and it is the best season of winter.
Unlike winter never rains during summers and temperatures are high, there are periods of heat waves, but generally temperatures are about 5 degrees lower than those in Athens, winds are rare except during August where there are northerly winds that keep journals for 3 days and called Maistro (those are called Meltemia in the Aegean)
However the weather in Corfu is unpredictable, it is an island very difficult for forecasters, almost any meteorological service can not predict the weather in Corfu, most systems completely fall out in their predictions.
So if you hear that we expect rains, then we probably have more sun, and if the prediction is good, most likely we will have rain.
The old fishermen still more accurate in their forecasts as they know better the local peculiarities.