The Aegadian Islands (Egadi in Italian) are located west of Sicily, a few miles from the coast, and are Favignana, Marettimo, Levanzo, plus some smaller islands. They are included in the marine protected area of the Aegadian Islands.
In the same area, and at an even shorter distance from Sicily, we find the Stagnone Islands, a group of islands located in a lagoon, on the coast near the airport of Trapani Birgi. The largest among them is called Isola Grande (Big Island), the second is Mozia, 700 metres (2,300 feet) away from the coast.
In both the Aegadian and the Stagnone Islands the climate is Mediterranean: winter is mild and relatively rainy, with sunny periods, but also waves of bad weather, characterized by wind and rain, while summer is hot and sunny, a little sultry but tempered by the breeze.
Although the temperature is generally mild, the wind, which blows especially in the cold half of the year, can increase the feeling of cold; in particular, the maestrale (north-west wind) and the ponente (west wind) are frequent, but there is also the scirocco (south wind) from Africa, which can bring dust and sand from the desert. Cold waves from the continent are rare, and in any case they not last long. Temperatures at night never drop below freezing (0 °C or 32 °F), and snowfalls are extremely rare.
The only island having elevations of some importance in the interior is Marettimo, where the highest peak, Monte Falcone, reaches 686 metres (2,250 feet).
For the data of these islands you can refer to the station of the nearby Trapani airport.
Average temperatures - Trapani

Trapani	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Trapani	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	8	8	8	10	13	17	20	21	19	16	12	9
Max (°C)	15	15	17	19	23	27	30	30	28	24	19	16
Min (°F)	46	46	46	50	55	63	68	70	66	61	54	48
Max (°F)	59	59	63	66	73	81	86	86	82	75	66	61

Precipitation is not abundant, and follows the Mediterranean pattern, with a maximum in autumn and early winter, and a pronounced minimum in summer, when it almost never rains. In Trapani, 495 millimetres (19.5 inches) of rain per year fall.
Here is the average precipitation.
Average precipitation - Trapani

Trapani	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Trapani	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	65	50	45	40	20	4	3	9	45	70	80	70	495
Prec. (in)	2.6	2	1.8	1.6	0.8	0.2	0.1	0.4	1.8	2.8	3.1	2.8	19.5
Days	9	8	7	6	3	1	1	1	4	7	8	9	64

The amount of sunshine in the Aegadian Islands is great in summer, when clear skies prevail; in winter, sunny periods, which can occur in this season as well, alternate with periods of cloudy skies.
Sunshine - Aegadian

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

The Aegadian coasts are generally formed by rocks overlooking the sea and caves, or by small bays, where you can sunbathe on a rocky shoreline. However, in the island of Favignana there also beaches.
The sea in the Aegadian Islands is warm enough for swimming from July to September, as generally happens in the Italian southern seas. In June, the sea is still a bit cool, while in October the water temperature is still decent, about 22 °C (72 °F).
Here are the average sea temperatures.
Sea temperature - Aegadian

Aegadian	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Aegadian	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	15	14	14	15	18	21	25	26	25	22	19	16
Sea (°F)	59	57	57	59	64	70	77	79	77	72	66	61

The best time to go to the Aegadian Islands for a beach holiday, is the summer, from June to August. For swimming, the best time is from July to September, although in September, which overall is still a good month (especially in the first half), the first disturbances occur. In June, as I said the sea is still a little cool, while in May it is still cold, and sometimes the air can also be a little too cool for sunbathing (perhaps because of the wind).

April and May are ideal for hiking, while in summer it can sometimes be too hot to stroll outdoors (especially in July and August: in June and September usually the heat is pleasant or at least bearable, obviously when the sirocco does not blow). In October, temperatures are mild, but the days are shorter and the weather can be rainy and windy.

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