What is the rainiest population in Spain

If you think of a Spanish territory associated with rain, surely the Cantabrian Coast or the Galician Coast come to mind with its green meadows, its constant storms, and that in those areas there must be the rainiest population in Spain. However, there is also a widespread idea, of Grazalema as the rainiest town in Spain, which makes it quite a climatic singularity in the south of the peninsular.

So what is the wettest population in Spain?

Well, it depends on the meteorological data we consider to establish this classification.

The possibly most representative figure of what can be called “the wettest population in Spain” is the average annual rainfall.

Average annual rainfall

The average annual rainfall indicates the average amount of rain received in a municipality throughout the year. The State Meteorological Agency (Aemet) has a wide base of stations with rainfall measurements, with data that in some cases date back to 1920.

Based on information from these stations, the distribution of the average annual rainfall in Spain is distributed as follows:

As we can see, the highest rainfall, with purple and violet colors (above 1,800 mm per year on average) is distributed along the western Galician coast, in the provinces of A Coruña and Pontevedra and in the northwest of Navarra, on the border of the province of Guipuzcoa. In a more specific way, they appear in other areas of the Cantabrian Coast, the Pyrenees and in Grazalema itself.

Based on the information on normal monthly rainfall values for the years 1981-2010, collected in the AEMET, the localities with the highest average rainfall are therefore in the northeast of Navarra, corresponding to:

1. Lesaka (Navarra): 2,366 mm per year
2. Articutza — Goizueta (Navarre): 2363 mm per year

They are followed in this list:

3. Vimianzo — Castrelo (A Coruña): 2,281.6 mm per year
4. Noia-Monte Irioite (A Coruña) 2,220 mm per year
5. Eiras Dam (Pontevedra): 2,093 mm per year

According to these data, other towns or measurement stations are located above 2,000 mm per year, such as Leiza, Arano or Arizcun, in Navarra or Serra de Outes in A Coruña.

All these measures are conditioned by the location of the stations themselves, and rainfall may be greater at high points in these or other municipalities.

And Grazalema? ... annual all-time high

Grazalema has a high rainfall rate, with 1971 mm of average annual rainfall. Based on this data, it could not be considered the point with the highest rainfall in Spain.

But there is a record, based on which, Grazalema station is the point with the most precipitation in the peninsula. This figure is the historical maximum of annual rainfall, for a given year, that is, the maximum amount of precipitation collected in a year on an absolute basis.

For this case, there are data with rainfall above 4,000 mm in a year in the Sierra de Grazalema. The next populations in this classification would correspond to populations also from the northwest of Navarra, such as Arruazu, Artikutza or Villarvacu, with record highs above 3,000 mm per year.

In this regard, there is a record of more than 5,000 mm in 12 months, at the Casas do Porto station, in A Coruña, although it is not a calendar year (between April 2000 and March 2001).

Torrential rains

If, on the other hand, we consider shorter time intervals, maximum rainfall is no longer (always) located in the north of the peninsular.

As we can see in this case, the highest rainfall is located in Levante, specifically in the Safor area, as well as in the north of Catalonia and in the Sierra de Grazalema.

The historic maximum amount of rain collected in one day corresponds to the 817 mm collected in Oliva (Valencia) on November 3, 1987 (although there is some controversy with this fact).

Data in the region of 600-700 mm in one day appear in some towns in the Levant and South of the Peninsula, such as Gandía and Barx (Valencia), Zúrgena (Almería) and Albuñol (Granada) and in some towns in the Canary Islands.

Regarding the maximum in one hour, the maximum was recorded recently, in the town of Vinaroz (2018). Other populations that show highs for small periods of time would be Huercal-Overa (Almería) with the maximum collected in 4, 5 and 6 hours, Oliva (Valencia) with the maximum collected in 9, 12 and 18 hours (in addition to the already mentioned maximum record for 1 day) or Javea, with the maximum collected for 2, 3, 4 and 5 days.

For maximums collected at longer intervals, starting at 7 days, the Grazalema area also has national highs, for measurements in 7 days, 15 days, 20 days (in Grazalema itself) and for 1 month and 2 months, in nearby Cortes de la Frontera, in Malaga. These data indicate the torrential nature and continuity of precipitation in this area.

On the other hand, comment on the common characteristics of areas with historic maximum rainfall, for short periods of time, since these are points embedded within a Mediterranean climate, close to the coast and in the environment of mountains of a certain height. In this case, rainfall is associated with the entry of moist air from the sea.

It could therefore be said that in the rainy months the Grazalema area has a rainfall similar to the highs of the Cantabrian area (or even higher, depending on the interval considered), although dry periods, which are less important in the north of the peninsular, are what makes this northern area where the annual highs are collected.

Based on average rainfall, for periods longer than three months, the highs are once again located in the north of the peninsula, mainly in Galicia and Guipuzcoa-Navarra. This rainfall is based on the entry of Atlantic fronts.

And in any case, although the classification of the wettest area or population in Spain depends in part on the data we consider as well as on information that can change continuously, the case of Grazalema is a place to consider because of its uniqueness within a context of much lower rainfall.

If you're traveling to some of the places mentioned above, don't forget your umbrella.