Weather and seasons
May and October, then April. May gives warm dry walking with long light before the heat arrives; October gives the same comfort with water back in the springs, a green Serra and refugis that are not full. April is close behind and the greenest.
This is a spring and autumn route, and the reason is heat rather than cold: April to early June and late September to November are the walking seasons, while July and August put 30 C on long unshaded limestone climbs with the springs dry. Winter walking is genuinely possible at low level, around 12 to 14 C, but read the altitude carefully, because the Serra de Tramuntana runs up to 10 C cooler than the coast and the published Mallorca figures are coastal. The other winter constraints are short daylight against long stages, wet dry-stone paving that is slippery, and cloud on the high traverses. Water is the recurring theme in every month: sources thin from June and refill with the autumn rain. Two services follow the season rather than the weather. The only bus along the high Ma-10 beside the trail, the Port de Soller to Lluc, Pollenca and Alcudia line, is marked a summer line on the operator's own page with no dates published, so outside the summer the Soller to Lluc stages, the highest and most exposed part of the route, have no bus escape at all; the year-round buses and the Soller railway reach only the two ends of that section. And the one operator selling luggage transfer to an independent walker states it is not possible between mid-June and the end of August, so a midsummer walker either carries everything or buys a package with the accommodation included.
Sóller reaches about 12 C with 5 hours of sun, and the Serra above it runs up to 10 C cooler, so the high stages are cold rather than mild. Fourteen rain days is the most of any month.
12°C high · 6°C low · 9.7Watch for: Cloud on the high traverses, wet polished rock, and short daylight against long stages.The coldest month by Sóller's own record, 13.5 C high against 9.7 C low, and colder again on the ridge. Walkable at low level, marginal high up.
13°C high · 6°C low · 10.8Watch for: Snow on Puig Major and the highest parts of the route, uncommon but not rare.Rain easing, temperatures climbing into the ideal range for a route with long exposed climbs, and the island at its greenest.
16°C high · 8°C low · 12.1Watch for: Unsettled spells can still close the high ground in cloud.One of the two best months. Comfortable on the long climbs, water still running in the torrents, everything open, and the Serra green before the summer burns it.
18°C high · 10°C low · 13.4Watch for: Easter fills the refugis, which are the constraint on this route.The best month on balance. Warm without being punishing, long light for the big stages, dry ground and water sources still reliable.
22°C high · 13°C low · 14.3Watch for: The first genuinely hot days on the south-facing ascents. Start early.Long days and reliable weather, but heat has become the thing you plan around and the springs are beginning to fail.
26°C high · 17°C low · 15Watch for: Water. Sources thin out from now on, so the day's carry has to be planned around the villages rather than the map.The driest month at about 10 mm, and 30 C on long limestone ascents with little shade is a heat-exhaustion risk rather than a hard day. The route is walkable in fragments before dawn, not as a traverse.
30°C high · 20°C low · 14.7Watch for: Springs dry, so water must come from villages, and the gap between them decides the day. Heat exhaustion is the named risk on this trail.As July with the island's holiday season at its height. Rated poor for walking while being Mallorca's busiest tourist month, which is precisely the distinction worth drawing.
30°C high · 21°C low · 13.6Watch for: Heat, dry springs, and afternoon storms building over the Serra late in the month.Improving quickly through the month as the heat breaks. The second half is close to April and May in quality, with the first rain putting water back in the torrents.
27°C high · 18°C low · 12.4Watch for: The gota freda pattern: autumn rain here can arrive as an intense downpour that floods the torrent beds the route crosses, rather than as steady rain.The autumn equal of April. Comfortable temperatures, water back in the springs, the Serra green again and the refugis no longer full. The trade is a real chance of heavy rain.
23°C high · 15°C low · 11.1Watch for: Flash flooding in the torrents after an intense autumn downpour. Do not cross a torrent in spate.The wettest month of the year at about 90 mm. Temperatures are still fine at low level and the high traverses spend a lot of the month in cloud.
18°C high · 11°C low · 10Watch for: Cloud and rain on the exposed high sections, and flooded torrent crossings.Mild at sea level, cold on the ridge with the Serra running up to 10 C below the coast, and the shortest days of the year against stages that need most of one.
14°C high · 7°C low · 9.3Watch for: Short daylight, and cold on the high traverses that the coastal forecast will not warn you about.