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Formentera sits 20 km south of Ibiza in the Balearic Islands and has a semi-arid Mediterranean climate: hot, dry summers and mild, wet winters. The island’s flat terrain (highest point just 192 m) means temperatures stay uniform across the island, and annual rainfall is low at about 450 mm spread over only 56 rainy days. This guide breaks down exactly what to expect every month of the year. For more, see our Formentera events and festivals guide.
Formentera Weather by Month: Average Temperatures
Daily mean temperatures in Sant Francesc de Formentera range from 11.8°C in January to 26.4°C in August. Winter nights drop to a minimum of 7.8°C in January and February, while August peaks at 30.4°C in the afternoon. July and August are the only months where the sea (24-26°C) is genuinely warm enough for comfortable swimming. For the full picture on when to plan the trip, see our best time to visit Formentera guide.
Month
Mean (°C)
Max (°C)
Min (°C)
Rain (mm)
Sea (°C)
January
11.8
15.9
7.8
40
15
February
11.9
16.0
7.8
30
14
March
13.6
17.8
9.5
40
15
April
15.8
20.0
11.6
40
16
May
18.8
23.1
14.6
25
18
June
22.8
29.7
18.4
15
21
July
25.6
29.7
21.5
5
24
August
26.4
30.4
22.4
25
26
September
23.7
27.6
19.8
45
24
October
20.2
24.0
16.3
70
22
November
15.8
19.6
12.0
55
19
December
12.9
16.8
9.0
60
16
Formentera Weather by Month: Winter (December to February)
Winter is mild but damp. December is the wettest month of the year at 60 mm over 6 rainy days, and January adds another 40 mm. Daytime highs reach 15.9°C to 16.8°C, so a jacket is enough during the day. Many bars and restaurants in Es Pujols and La Savina close from November to Easter, and ferry frequency from Ibiza drops to every 1-2 hours. Sea temperature falls to 14-15°C, so swimming is off the table unless you have a wetsuit. For more, see our Formentera neighborhoods guide.
Formentera Weather by Month: Summer (June to August)
Summer is hot and dry, with July recording just 5 mm of rain across a single day. August averages 26.4°C and pushes past 30°C on the hottest afternoons. The sea warms to 26°C by August, making Ses Illetes and Es Pujols beach ideal for long swims. June gets 11 hours of sunshine a day and virtually no rain (15 mm), but the sea is still a cool 21°C. UV levels are extreme from 11am to 4pm, and sun loungers at Ses Illetes fill by mid-morning. See our things to do in Formentera guide for beach-by-beach detail. For more, see our Formentera travel tips guide.
Formentera Weather by Month: Spring and Autumn
Spring (March to May) warms from 13.6°C to 18.8°C, and April still carries 40 mm of rain over 6 days. Autumn is the wettest season: October is Formentera’s rainiest month overall at 70 mm over 5 days, with September at 45 mm and November at 55 mm. September stays warm (mean 23.7°C, sea 24°C) which keeps beaches open, but sudden autumn storms are common. For more, see our where to stay in Formentera guide.
