Mediterranean sub-tropical climate predominates in the Balearic archipelago, with an annual rainfall of between 350 mm and 650 mm. Snowfalls are very rare and slight, principally on the mountain peaks. Temperatures are pleasant throughout the year. All of this, along with an average of 300 sunny days a year, means that the Balearic Islands have one of the most pleasant climates in Europe. Nevertheless, there are significant differences between the regions various islands.
The climate on Mallorca
Typically Mediterranean, with mild average temperatures and a seasonal rainfall pattern, the summer being hot and dry. Rainfall varies from one part of the island to the other, from 350 mm in the south to 1,500 mm in the high mountains of the Tramuntana Sierra, but in most of the island, it is between 450 and 650 mm. 40% of total annual rainfall occurs during the autumn, from September to November, 25% in spring from March to May and the same in winter from December to February, while only 10% occurs during the summer from June to August. The rainfall pattern is, however, very irregular and varies considerably from year to year, to the extent that droughts can occur. The majority of the rain falls over a few days, with intense rainfall occurring during the autumn, the rest of the year being less intense. Average annual temperatures are between 16 and 18ºC, except in the high mountains. Average maximum daytime temperatures are 29/31ºC during the summer and average minimum night-time temperatures during the winter are 5/9ºC, even though almost every year there are extreme periods when temperatures rise above 35ºC and fall below -2ºC; on rare occasions temperatures can reach 41ºC in summer and fall to -6ºC in winter.
Mallorca's main physical characteristic is the sea, which is deep, protected and relatively warm, with surface temperatures that reach 26 ºC in August and do not fall below 14ºC in winter. The sea regulates temperatures and ensures that seasonal variations are not as extreme as the same latitude on the mainland.
Northerly winds called the Mistral (NW) and Tramuntana (N) predominate during the winter. During the summer months, the winds blow mainly from the south and are known as the Xaloc (SE), Mitjorn (S) and Llebeig (SW).
Embat is the name Mallorcans give to the sea breeze, a wind caused locally by the land warming up faster than the sea during the day. Hot air over the island tends to rise and draw cooler air from the sea inland. This means that daytime temperatures during the summer are not too high along the coast, as long as there is no wind blowing in the opposite direction to the 'embat'.
The climate on Minorca
Minorca has a typically Mediterranean climate all year round, with no extreme temperatures. Winters are mild and wet and the summers are hot and dry. Average temperatures are: January 10º; February 10.5º; March 12.2º; April 14.5º; May 17.5º; June 21.5º; July 24.2º; August 24.5º; September 22.6º; October 18.4º; November 14.4º and December 11.9º.
The most important weather phenomenon on the island is the northerly wind, the famous Tramuntana, a strong dry wind that can blow at any time of year, although during the winter months it can reach more than 100 kilometres per hour. These gusts are responsible for Minorca being called 'the windy island', although the Tramuntana does not always blow this strong. On the contrary, during the summer it becomes a light breeze much appreciated by the island's inhabitants, as it reduces summer temperatures and the humidity in the air, bringing days with a cleaner atmosphere.
As far as rainfall is concerned, the yearly average is 650 mm, which can vary from year to year and where you are on the island. Normally the highest rainfall occurs during the autumn.
The climate on Ibiza and Formentera
Temperatures on these two islands (collectively known as the Pitiusas) are reasonably even and high. Ibiza's yearly average is 18-19ºC and average temperatures do not fall below 10ºC. In June, July, August and September the average exceeds 25ºC. On Formentera the averages are slightly higher: average maximum temperatures never reach 30ºC and are higher during autumn than during the spring, while the lowest average temperatures are in December, January and February. Annual thermal variation is 14ºC on Ibiza and 13ºC on Formentera (one of the lowest in the Balearics), while the annual average variation is between 5 and 6ºC.
Above all, we are talking about a climate with high average temperatures, mild winters, long summers, low annual average temperature variation and a high level of exposure to the sun (2,800 hours annually).
Rainfall is uneven and scarce, a total of 380 mm. on Ibiza and 350 mm. on Formentera. In no month is there excess water; indeed the opposite is the case, as there is a water deficit for nine months on Ibiza and ten on Formentera.
Prevailing winds are from the W-SW in winter, and from the E in summer, because of thermal depression over the centre of the Iberian Peninsula. These islands are not big enough to generate their own sea breezes.