Corsica map

The climate of Corsica is Mediterranean on the coast, with mild, rainy winters and warm, sunny summers, while in inland areas it gradually becomes colder with increasing altitude. In fact, the interior of the island is largely mountainous; the highest peak is Monte Cinto, 2,706 meters (8,878 feet) high. At high altitudes, snowfalls can occur in winter and early spring, and sometimes, it can snow even in the first half of May.
In the major cities that are located on the coast, like Ajaccio, Calvi, Bastia, Bonifacio, Porto Vecchio, Sartena, the climate is similar, ie Mediterranean. Corte, which sits at 400 meters (1,300 feet) above sea level, in the interior of the island, is instead a bit colder in winter, while in summer, it can be hotter during the day, with some more thunderstorms, but also a bit cooler at night.
Here are the average temperatures of Ajaccio, the largest city, located on the west coast.
Ajaccio - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)445711141717151285
Max (°C)141415172125282826221715
Min (°F)393941455257636359544641
Max (°F)575759637077828279726359

The island is pretty windy, not only for the summer breezes, but also because it can be affected by the north-western wind coming from the Rhone Valley, the Maestrale (or Mistral), which blows in gusts, especially on the west coast and on the Strait of Bonifacio, while the Libeccio, the most frequent wind which blows from the south-west, is moist and is usually followed by bad weather conditions.
On the mountain slopes of the interior, precipitation is more abundant, and summer thunderstorms are more likely; for this reason, some inland areas are very rainy and covered with forests. On the other hand, along the coast, annual precipitation does not exceed 700 millimeters (27.5 inches), and follows the Mediterranean pattern, with a maximum from October to February, a gradual decrease in spring, and a minimum in summer.
Here is the average precipitation in Ajaccio.
Ajaccio - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)605555654025102055909570640
Prec.(in)2,42,22,22,61,610,40,82,23,53,72,825,2
Days87886312588872

Winter, from December to February, is mild and rainy on the coast, where the average temperature in January and February is about 8/9 °C (46/48 °F). In the mountains, where ski resorts are found, winter is cold, with quite frequent snowfalls. The wind blows frequently. Sometimes, the wind blowing from the Rhone Valley is colder than usual because the air mass is of Polar or Siberian origin. In these cases, there may be snowfalls even in the plains, especially in the northern part of the island. On the plains and the coasts, light frosts may occur during cold waves: generally, the temperature does not drop below -2/-3 °C (27/28 °F), although the records are lower: -8 °C (18 °F) in Ajaccio, set in February 1986.

Spring is initially cool and unstable in March and April, while it becomes gradually milder and sunnier as the weeks pass, and it becomes generally pleasant by May.

Summer, from June to August, is warm to hot and sunny along the coasts, while in inland areas, it becomes progressively cooler with increasing altitude, and there is also a higher chance of afternoon thunderstorms. These thunderstorms can sometimes reach the coasts. On the coasts, the heat is usually acceptable, since it is a bit moist but also tempered by the breeze. Sometimes, however, there may be waves of African heat, usually of short duration, with peaks around 38/40 °C (100/104 °F).

Autumn is initially mild or pleasantly warm, and gradually becomes cooler; it is also quite rainy. The first disturbances occur in September, and become more frequent in October. November is typically a cloudy and rainy month, as normally happens also in north-central Italy.

Ajaccio

The amount of sunshine in Corsica is very good in summer, especially along the coasts, when clear skies prevail, while it's not high from November to February, when Atlantic depressions frequently pass over the island. However, sunny periods can occur even in winter. Here are the average sunshine hours per day.
Ajaccio - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours457791112119654

Corsica is the French region where the sea reaches the highest temperature, ie 23 °C (73 °F) in July and September and 24 °C (75 °F) in August, while it is still cool in June. Here are the average sea temperatures.
Ajaccio - Sea temperature
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Temp (°C)141414141720232423201815
Temp (°F)575757576368737573686459

Best Time


If you want to visit cities, you can choose the period from mid-April to mid-June, and the month of September, since it can be very hot in summer, though it rarely happens.
If you plan to go hiking in the mountains, you can go from June to September.
The best months for a beach holiday are July and August. In June and September, you can go, but it can sometimes be a bit cool in the evening, or it can rain, and in June, as mentioned, the sea is still cool. For cool evenings and windy days, you can bring a sweatshirt.
In summer, in inland areas, where thunderstorms can break out, even if the weather is fine in the morning, care must be taken to lightning (therefore, it's better not to take shelter in the forests or under the trees), as well as to the possible sudden swelling of streams during heavy rains.