April, May, October and November have mild weather, with daytime highs of 20 to 25 degrees and fewer visitors than in summer. July and August are the hottest and busiest months, with highs around 31 degrees and almost no rain. Winter is mild, though it has about five rainy days a month.
Highs rise from about 20 degrees in March to nearly 25 in May. It is a comfortable time for the hill sights, with around three to five rainy days a month.
What to wear: Bring a light jacket for the evening and comfortable shoes for the climbs.
Summer
21 to 30 °C · about 0 rainy days a month
Highs reach 28 degrees in June and about 31 in July and August, with almost no rain. Evenings are warm, and the beach is at its busiest.
What to wear: Wear light clothes, a hat and sunscreen, and carry water for the fortresses.
Autumn
15 to 24 °C · about 4 rainy days a month
September is still warm at about 28 degrees, then highs ease to 24 in October and 20 in November. Rain returns at about five days a month by November.
What to wear: Light layers work, with a rain jacket from October on.
Winter
8 to 18 °C · about 5 rainy days a month
Highs stay around 17 to 18 degrees, with lows of 8 to 9. It rains on about five days a month, and many days are clear.
What to wear: A light coat or warm sweater is enough, plus a rain jacket and shoes with grip on wet stone.
If it rains
A rainy day moves the visit indoors: the Picasso museum, the Pompidou, the Thyssen museum, the Cathedral and the municipal museum are all covered. The Alcazaba and Gibralfaro stay open, but the stone paths get slippery. Rain usually passes in a few hours, so a short wait often works.
Summer midday is hot, and the Alcazaba and Gibralfaro have little shade, so go at opening or late in the day. Use the museums and the Cathedral as shade in the middle of the day. Carry water and wear a hat from June to September.