In Sardinia, an island of Southern Italy, the climate is Mediterranean, with mild and fairly rainy winters, and hot and sunny summers, a bit sultry but tempered by sea breezes. On coasts and plains, the average temperature of January and February is about 10 °C (50 °F), while that of July and August is about 25 °C (77 °F).
The rains are not abundant, given that they typically fluctuate from 400 to 550 millimetres (15.5 to 21.5 inches) per year on the coast (but locally they can drop even below, for instance in the southeastern tip of the island), and follow the Mediterranean pattern, that is, they are more common in autumn and winter, they gradually decrease during spring, and hit a low in summer, when it almost never rains. In inland areas, rainfall locally exceeds 700 millimetres (27.5 inches) per year in hilly areas, and 1,000 mm (40 in) in the mountains.
Here is the average precipitation in Cagliari, the main city, situated on the coast, in the southern part of the island.
Average precipitation - Cagliari

Cagliari	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Cagliari	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	45	55	45	35	25	10	3	10	30	55	55	55	425
Prec. (in)	1.8	2.2	1.8	1.4	1	0.4	0.1	0.4	1.2	2.2	2.2	2.2	16.7
Days	8	8	7	6	4	2	1	1	4	6	8	8	62

Sardinia is a windy island, especially from October to April, because of the Maestrale, the northwest wind, which blows from France (where it is called Mistral), and affects particularly the western part and the Strait of Bonifacio, but also because of the "Ponente", which blows from the west. In summer, sea breezes blow, but they are welcome because they make the heat more bearable; on other occasions, the "Scirocco" can blow from the south-east, bringing heat waves from Africa, which are felt mainly in inland plains and valleys, with peaks of 40 °C (104 °F) and more.
In the interior, the climate becomes gradually colder with increasing altitude, as there are hills and mountains, and as mentioned in some areas the rains are also more abundant, so that thick forests are found. The highest peak, 1,834 metres (6,017 feet) high, is located in the Gennargentu Massif, where in winter snowfalls are quite frequent.



The island is quite sheltered from cold waves; along the coasts and in the plains, snowfall is quite rare, but can occur in the coldest winters (as happened in January 1985 and February 2012), more easily in the north of the island. An exception is Costa Smeralda ("Emerald Coast", see Olbia), in the northeast, where snowfalls, though usually not abundant, are a bit more frequent. Night frosts in the plains are rare, and when they occur, they are light: generally the temperature does not drop below -2/-3 °C (27/28 °F). In inland areas instead, already at hill altitudes (see Nuoro, Macomer, Tempio Pausania), snow is relatively more frequent and abundant.
Here are the average temperatures of Alghero, located on the coast, in the north-west of the island.
Average temperatures - Alghero

Alghero	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Alghero	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	6	6	7	8	12	15	17	18	16	13	9	7
Max (°C)	14	14	16	18	22	26	29	30	27	22	18	15
Min (°F)	43	43	45	46	54	59	63	64	61	55	48	45
Max (°F)	57	57	61	64	72	79	84	86	81	72	64	59

In the small islands and the most exposed coasts, the climate is particularly mild. Here, for example, the average temperature of Guardiavecchia, in the island of La Maddalena, where 470 mm (18.5) of rain per year fall, with a maximum in December of 75 mm (2.9 in), and a minimum in July of 12 mm (0.45 in).
Average temperatures - Guardiavecchia

Guardiavecchia	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Guardiavecchia	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	8	8	9	10	14	17	20	20	18	15	11	9
Max (°C)	13	13	14	16	19	23	27	27	24	20	16	13
Min (°F)	46	46	48	50	57	63	68	68	64	59	52	48
Max (°F)	55	55	57	61	66	73	81	81	75	68	61	55

In inland plains, the climate becomes slightly more continental. Here, for example, the average temperature of Decimomannu, about 20 kilometres (12 miles) north-west of Cagliari.
Average temperatures - Decimomannu

Decimomannu	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Decimomannu	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	4	5	6	8	11	15	18	19	16	13	9	6
Max (°C)	14	15	17	19	24	28	32	32	28	23	18	15
Min (°F)	39	41	43	46	52	59	64	66	61	55	48	43
Max (°F)	57	59	63	66	75	82	90	90	82	73	64	59

As we said, at higher altitudes the weather gets colder. Here are the average temperatures of Fonni, located north of Gennargentu, at 1,000 metres (3,300 feet) of altitude.
Average temperatures - Fonni

Fonni	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fonni	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	2	2	3	5	9	13	16	17	13	10	6	3
Max (°C)	7	7	10	12	17	22	26	26	22	16	11	9
Min (°F)	36	36	37	41	48	55	61	63	55	50	43	37
Max (°F)	45	45	50	54	63	72	79	79	72	61	52	48

The sunshine amount in Sardinia is very good in summer, especially along the coast, when clear skies prevail, while it's not so high from November to February; however, some sunny periods can occur also in winter.
Here are the average daily sunshine hours in Cagliari.
Sunshine - Cagliari

Cagliari	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cagliari	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	4	5	6	7	9	10	11	10	8	6	5	4

The temperature of the sea is fairly uniform in the island, and just lower in the western part; the sea is warm enough for swimming from July to September; in June and October it's instead a bit cool. Here, for example, the temperature of the sea at Porto Cervo, on Costa Smeralda.
Sea temperature - Porto Cervo

Porto Cervo	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Porto Cervo	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	14	14	14	14	17	20	23	25	23	20	18	15
Sea (°F)	57	57	57	57	63	68	73	77	73	68	64	59

For beach life, the best time to visit Sardinia is summer, from June to August. For swimming, the best time is from July to September, although in September, which in any case is still a good month (especially in the first half), the first periods of bad weather occur. In June, as mentioned the sea is still a bit cool, while in May it's even cold, and sometimes the air can be a little cold for sunbathing as well.
April and May are advisable for hiking and for visiting cities, while in summer it can sometimes be too hot to get around with ease. In October, temperatures are mild or pleasantly warm, but the days are shorter and the weather can be rainy and windy.