The year in the Algarve, month by month
The figures come from the Faro airport station, 1991–2020 series: 455.1 millimetres a year over 48.9 days and 3,044.4 hours of sunshine. Since rain barely intervenes in summer, the scoring crosses sunshine, water temperature and crowds.
The Algarve is sold as a sun destination, and in its case the label is justified by the numbers. What is interesting is not how much sun there is, but how unevenly the rain is spread and what that implies for choosing the month.
01 Forty-nine days
The figure that best sums up this coast's climate is not the rainfall total, which at 455.1 millimetres a year is unremarkable. It is the number of days: 48.9. That is, on thirteen days out of every fourteen it does not rain.
And those days are concentrated. In July it rains on 0.2 days and in August on another 0.2: between the two months they do not add up to half a rainy day. In June, 0.8 days. The whole summer accumulates 9.0 millimetres.
Sunshine follows: 3,044.4 hours a year, with 360.6 in July alone, almost twelve a day. In December, the worst month, there are still 159.0 hours, more than five a day.
July and August add up to less than half a rainy day between them: summer here is not dry, it is nil.
02 The water arrives in winter
The annual distribution surprises anyone expecting the classic Mediterranean pattern. The wettest month is neither January nor November: it is December, with 90.0 millimetres over 7.0 days. Then come November, with 75.5, and October, with 56.0.
Between November and February 57 per cent of the annual water falls. And that water is what sustains everything else: the wells of the barrocal, the almond trees, the carobs and the sheet of water in the salt pans.
For the traveller winter has an advantage almost nobody uses: it is not cold. January's average high is 16.3 degrees, the low 8.3, and the station's absolute cold record is −0.3. You can be outdoors all day on six days out of seven.
03 The sea runs two months behind
There is a lag that decides the month of a trip more than air temperature does. The sea has enormous thermal inertia, so its maximum does not coincide with the air's: it arrives a few weeks later.
On the south coast, the water reaches its warmest in August, at around 21.7 degrees on average, and September keeps practically all of that warmth while the air has already dropped from 29.2 to 26.4 degrees.
The corollary is awkward for anyone travelling in spring: in May there are highs of 23.5 degrees and splendid weather, but the water still carries the cold accumulated over winter. June and May are magnificent for everything except swimming.
04 And the other calendar, the one made of people
Because the weather is good almost always, the factor that really separates one month from another is not meteorological. It is the crowds, and they concentrate brutally in July and August.
That produces a paradox worth accepting: the two months with the best rain and sunshine figures are the two worst for travelling. July has 0.9 millimetres of rain and 360.6 hours of sunshine, and it is exactly when the well-known beaches of the south coast fill up.
The solution is not to change destination but to change month. September has 21.5 millimetres of rain over 1.9 days, highs of 26.4 degrees and the water still at its best: almost the same product without the main drawback.
05 The heat, which comes from the east
The Algarve's average highs are moderate for such a southern latitude: 29.4 degrees in July and 29.2 in August. The sea damps down both cold and heat.
But there is one exception that shows up in the extremes. Faro's absolute record is 44.3 degrees, recorded in July, and at Vila Real de Santo António, on the eastern border, it reaches 44.4. That is almost fifteen degrees above the average high.
Those episodes do not come from the sea but from inland, with easterly or north-easterly wind bringing overheated continental air. They last a few days, but it is worth knowing they exist if the plan includes walking inland in summer.
06 How to choose the month
If the trip includes the beach, September without argument. It is the only month that combines warm water, air at 26.4 degrees, 279.1 hours of sunshine, fewer than two rainy days and crowds already retreating.
If the trip is about walking and the interior, March, April and May. Rain drops from 46.8 to 26.2 millimetres, sunshine rises from 242.6 to 305.0 hours and highs stay between 18.9 and 23.5 degrees: there is no better stretch for the barrocal or the western paths.
And if you are only after winter sun, it works better than you would think. With 5.4 to 7.0 rainy days a month, highs of 16.3 to 17.1 degrees and more than five hours of sunshine a day, from December to February you are outdoors nearly every day. The only thing closed is the sea.
The year's four stretches
From 41.9 to 90.0 millimetres a month over 5.4 to 7.0 days: 57 per cent of the annual rain falls here. Highs of 16.3 to 19.6 degrees and never a frost: Faro's cold record is −0.3.
Rain falls from 46.8 to 5.1 millimetres and sunshine rises from 242.6 to 326.9 hours. Highs of 18.9 to 26.8 degrees. The only drawback is the water, which in May has still not warmed up.
0.9 and 3.0 millimetres of rain over 0.2 days each, with 360.6 and 344.9 hours of sunshine. The weather is unbeatable and precisely for that reason it is when peak crowds and peak prices coincide.
21.5 and 56.0 millimetres over 1.9 and 6.0 days, with highs of 26.4 and 23.3 degrees. The sea keeps the heat it built up in summer and the crowds have thinned: the best crossing of the year.
