Quick answer
Yes, but start at sunrise. Sea-level highs hit 26–28 °C in July–August and trails on the south coast are exposed. The classic high routes (PR1 Pico do Arieiro–Pico Ruivo, PR9 Caldeirão Verde) are 8–12 °C cooler than Funchal and ideal in summer if you're on the trail by 08:00.
Context
Madeiran summer is dry and stable, which is excellent for hiking, but the south-coast and east-tip trails (Ponta de São Lourenço in particular) have almost no shade and can become punishing by midday. The fix is simple: arrive early, carry 2 L of water, and finish before noon.
The high-mountain levadas, Caldeirão Verde, Caldeirão do Inferno, 25 Fontes, stay cool and shaded under the laurisilva canopy even in August. They're the best hiking on the island in peak summer.
Trail status changes weekly. Closures from rockfall or maintenance are posted by IFCN and visible on our live levada conditions page.