May, June, September and October are the best months, with afternoon highs between 23 and 27 degrees. July and August are hotter and busier, with highs near 30 degrees and warm nights. Winter is mild, with highs near 16 degrees, but rain falls on six or seven days a month from October to January.
Highs rise from about 18 degrees in March to 23 in May, with three to five rain days a month. It is comfortable for walking and the castle views are clear.
What to wear: Bring a light jacket for the mornings and comfortable shoes for the old town.
Summer
22 to 29 °C · about 1 rainy days a month
Afternoons reach 27 to 30 degrees from June to August, and July has less than one rain day. Plan visits for the morning and rest at midday.
What to wear: Wear light clothes, a hat and sunscreen, and carry water.
Autumn
16 to 24 °C · about 6 rainy days a month
September is still warm at about 27 degrees, October settles near 24 and November near 19. Rain days increase from five in September to seven in November.
What to wear: Bring a light jacket for the evenings and a waterproof layer from October.
Winter
9 to 16 °C · about 6 rainy days a month
Highs sit around 16 degrees and lows near 8 to 10, with five or six rain days a month. The cathedral closes early and several sights are closed on Mondays, so the day is shorter.
What to wear: Wear a warm jacket and shoes with grip, since wet stone is slippery.
If it rains
Rain slows the walk but does not close the city. The cathedral, the Almudaina palace, Es Baluard, the Museu de Mallorca, the Miró foundation and the Olivar market are all indoors. Save Bellver Castle and the sea wall for a dry morning.
Summer afternoons are hot and the sea wall has little shade, so keep outdoor walking for the morning and after 18:00. The cathedral, the museums and the market work as cool breaks. Carry water and wear a hat.