Madeira does not have a weather: it has several at once. Funchal can be 24 °C and sunny while Santana is in cloud and Pico do Arieiro is 8 °C with a wind. The north is greener and wetter; the south is drier and warmer; the mountains make their own rules.
The rule that works: check the live webcams in this app (Explore, then Weather & live webcams) before you drive up, and pack in layers.
- A light waterproof jacket, always, even in August.
- Proper shoes for levadas and viewpoints; the paths are wet and the stone is slippery.
- Sun cream and a hat. The sun is strong at this latitude even when it feels mild.
- Swimwear. There are sea pools and beaches even in winter: the sea is 18–19 °C in February and 23 °C in September.
- Something warm for the mountains and for evenings on the north coast.
