The year in Palma, sea included
All the figures are the capital's: 470.1 millimetres of rain a year over some 53 days, 2,858 hours of sunshine and a mean of 18.5 degrees. The scoring crosses three things: how much it rains, how much light there is, and how warm the water is.
There is one idea taken for granted about these islands that is worth reviewing before choosing dates: that the climate here is Mediterranean, with what that implies of wet winters and dry summers in reasonable proportion.
Palma's official classification says something else. The capital is catalogued as a hot semi-arid steppe climate bordering on the dry-summer Mediterranean type. Which is to say: technically it sits on the boundary, and on the dry side.
01 The classification that surprises
The figure behind that label is the annual total: 470.1 millimetres. For an island that appears in photographs with pine woods, green terraces and orchards, that figure is low. And the wet days confirm it: some 53 in the whole year, one in seven.
Sunshine, by contrast, is abundant: 2,858 hours a year. And the annual mean temperature is 18.5 degrees, with highs running from 15.7 in January to 30.2 in August. It is a comfortable, bright climate with little water.
It is worth stressing that this figure is Palma's, on the southern plain. The Serra de Tramuntana, to the north-west, catches considerably more water, and much of the island's farming history comes from that difference between mountain and plain.
02 A summer of almost total drought
July marks the extreme: 5.1 millimetres of rain over 0.6 days. Put another way, in an average July it rains for a little over half a day. And that same month records 353 hours of sunshine, the calendar's maximum.
June and August follow, with 13.9 and 21.7 millimetres. Between the three they add up to 40.7 millimetres: less than nine per cent of the annual water in the middle third of the year. It is a full-blown summer drought.
For a traveller, this is an unusual guarantee: if the plan is beach and sun, July is practically certain. The price, of course, is that the same month is the busiest and the hottest, with average highs of 29.7 degrees.
03 And an autumn that concentrates the water
What makes this a semi-arid climate is not only that it rains little, but that the little that falls is concentrated. September leaves 60.5 millimetres, October 72.6 and November 67.8. Between the three they add up to 200.9, almost 43% of the annual total.
And the jump is abrupt. From August to September rain goes from 21.7 to 60.5 millimetres, almost triple in one month. October, with 72.6, is the wettest month of the year, ahead of January's 44.4.
That detail dismantles the automatic advice of going in October for low season with good weather. Here October is not a dry transitional month: it is the month when it rains most, and November adds the record for wet days, 7.2, and the sunshine minimum, 162 hours.
04 The sea lags behind the air
There is a second series almost nobody checks that decides half the experience: water temperature. In Palma it runs from 13.9 degrees in February to 26 in August, and its curve is shifted relative to the air's.
Compare May with October. In May the air gives highs of 23 degrees and the water is at 18.9. In October the air drops to 24 — practically the same — and the water rises to 22.7. Almost four degrees more sea with the same air.
The problem is that this October of warm water comes with 72.6 millimetres of rain. Which is to say: the month when the sea is best is the month when the sky is worst. That tension is what you have to resolve when choosing dates.
05 What the drought built
It is worth looking at the landscape with this figure in mind, because it explains what you see. On an island of 470 millimetres a year, water is administered: collected, channelled and stored. Nothing green is spontaneous.
The Serra de Tramuntana, which peaks at Puig Major's 1,445 metres, is what intercepts the water and what filled up with terraces, walls and channels. That hand-built landscape has been a World Heritage Site since 2011, and it exists for the same reason Palma is semi-arid.
So the 470-millimetre figure is not a loose meteorological fact: it is the explanation for the island's appearance. The mountain terraces are the agricultural answer to a climate that does not give enough water on its own.
The year's four stretches
31.6 and 13.9 millimetres over 3.1 and 1.9 days, with 298 and 327 hours of sunshine and highs of 23 and 27 degrees. The water rises from 18.9 to 22.5. The only stretch with a safe sky, reasonable heat and a usable sea at once.
5.1 and 21.7 millimetres, 353 and 319 hours of sunshine and the sea at its maximum, 24.9 and 26 degrees. It is the year's best swimming and also the peak of heat — 30.2 degrees — and of crowds. A practically guaranteed sky.
60.5, 72.6 and 67.8 millimetres: almost 43% of the annual rain in three months. October is the wettest month of the year and November the least sunny, 162 hours. In exchange, the sea holds at 25, 22.7 and 19.7 degrees.
Between 29.2 and 49.3 millimetres a month and from 152 to 249 hours of sunshine. Highs never drop below 15.7 degrees, so it is not cold. But the sea falls to 13.9 in February and the light is the scarcest in the calendar.
06 How to choose the month
If the trip is about swimming, the answer is July or August, with the water at 24.9 and 26 degrees and practically no chance of rain. It is the obvious option and also the most expensive and crowded.
If the trip is about everything else — walking, seeing the island, eating outdoors without sweating — the answer is June: 13.9 millimetres over fewer than two rainy days, 327 hours of sunshine, highs of 27 degrees and the sea already at 22.5. It is the month with the fewest drawbacks in the calendar.
And the rule worth inverting against the usual advice: if you want low season, look at May rather than October. May leaves 31.6 millimetres over 3.1 days and 298 hours of sunshine; October, 72.6 over 6.3 days and 208 hours. That is more than twice the water and ninety hours less light for the same off-season price.
Bärbel Miemietz In Arusha there are two dry seasons a year, and hardly anyone uses the second
Ngguls In Kunming the temperature does not change all year: the only thing that changes is the sky
Juan Pelizzatti