Why temperature is not the question
Funchal stays within a narrow band all year: the difference between February and August is smaller than the difference between Funchal and Porto Moniz on the same afternoon. Searching by month is searching at the wrong end — the axis that matters runs across the island, not through the year.
What does change over the year: rainfall in the north, day length and with it usable walking time, and how full the island is.
The festivals
Carnival in February, the flower festival in spring, the wine festival in late summer, and the New Year’s Eve fireworks over the bay of Funchal. All four move prices and availability noticeably, the fireworks most of all — that is booked a year ahead.
Walking
The high ground is colder in winter and more often in cloud, which makes the paths slipperier. In summer the view from the ridge is more reliable, but there is no space left at the well-known trailheads by mid-morning.
Spring and autumn are the compromise: light for long enough, rarely crowded, and the north still has water in the waterfalls.
The actual rule
The month decides less than the morning does. Plan per coast and decide at breakfast — rain in Santana and sun in Funchal is the normal case, not the exception.
