relocoast
Dataset

Monthly sea temperature

Guides answer the water question with one figure for a whole coast. The Costa Blanca runs two hundred kilometres and the Canaries are seven islands, so one figure is not an answer. Here each of the 132 places has its own grid cell: 80 distinct monthly profiles.

What the figure does not mean

A grid cell is a square of roughly 25 kilometres, and a coastal one averages in the open sea. It cannot see a bay, an inlet, or cold water rising at a headland. That is enough for a monthly normal and not enough for “what is the water like at this beach today”.

An enclosed lagoon is a case of its own. The Mar Menor is cut off from the sea by a sand bar; its water is shallower and saltier, warmer than the open sea in summer and colder in winter. The nearest sea cell lies on the far side of the bar, so for the three towns on the lagoon this dataset describes water they do not swim in. They are marked in the table.

The table

From the longest season to the shortest. The season counts months at or above 20 °C — below that only the hardy go in.

Download CSV
PlaceMonths at 20 °C+Yearly lowYearly peakCell, km
Santa Cruz de La Palma 1019.7 °C24.4 °C12.4
Los Llanos de Aridane 1019.7 °C24.4 °C5.5
Puerto de la Cruz 1019.5 °C24.2 °C8.7
San Sebastián de La Gomera 1019.7 °C24.1 °C4
Santa Cruz de Tenerife 1019.4 °C24.1 °C15.6
Adeje / Costa Adeje 1019.5 °C24 °C11.9
Mogán 919.2 °C23.6 °C9.7
Maspalomas 919.2 °C23.6 °C13.3
Las Palmas de Gran Canaria 819.1 °C23.6 °C6
Telde 819.1 °C23.5 °C14.3
Antigua 818.7 °C23.2 °C12.1
Pájara 818.7 °C23.2 °C3.3
Yaiza 818.6 °C23.2 °C13.8
Arrecife 818.5 °C23.1 °C12.3
Puerto del Rosario 818.6 °C23.1 °C13.9
Tías 818.5 °C23.1 °C9.2
Corralejo 818.6 °C23.1 °C12.6
Teguise 718.5 °C23.1 °C9.6
Palma de Mallorca 614.7 °C27.1 °C21.7
Castellón de la Plana 514 °C27.1 °C13.9
Vinaròs 513.6 °C27.1 °C13.3
Alicante 514.6 °C27.1 °C9.9
Peñíscola 513.6 °C27.1 °C2.8
Santa Pola 514.6 °C27.1 °C9.6
Benicàssim 513.8 °C27.1 °C9.1
El Campello 514.6 °C27.1 °C6.2
Guardamar del Segura 514.6 °C27.1 °C4.7
Pollença 514.4 °C27.1 °C18.9
Sagunto 514.1 °C27 °C13.7
San Javier lagoon: figure is the sea beyond the bar514.7 °C27 °C19.9
San Pedro del Pinatar lagoon: figure is the sea beyond the bar514.7 °C27 °C15.1
Torrevieja 514.7 °C27 °C12.6
Benidorm 514.6 °C27 °C18.5
Orihuela Costa 514.7 °C27 °C11.6
Alaior 514.3 °C26.9 °C6.6
Valencia 514.1 °C26.9 °C24
Alcúdia 514.4 °C26.9 °C21.9
Sant Antoni de Portmany 514.7 °C26.9 °C13.6
Santa Eulària des Riu 514.7 °C26.9 °C14.5
Sant Josep de sa Talaia 514.7 °C26.9 °C8.8
Ibiza (Eivissa) 514.7 °C26.9 °C5.3
Águilas 514.8 °C26.8 °C5.5
Mazarrón 514.8 °C26.8 °C20.5
Gandía 514.2 °C26.8 °C18.3
Los Alcázares lagoon: figure is the sea beyond the bar514.8 °C26.8 °C25.2
Cullera 514.2 °C26.8 °C12
Cambrils 513.5 °C26.8 °C22
Maó / Mahón 514.3 °C26.8 °C9.4
Dénia 514.3 °C26.8 °C4.2
Es Castell 514.3 °C26.8 °C7.2
Calpe / Calp 514.4 °C26.8 °C7.3
Altea 514.4 °C26.8 °C15.7
Ciutadella de Menorca 514.2 °C26.8 °C14.2
Jávea / Xàbia 514.3 °C26.8 °C10.2
Moraira 514.4 °C26.8 °C7.1
Formentera 514.8 °C26.8 °C10.1
Reus 513.6 °C26.7 °C22.7
Tarragona 513.6 °C26.7 °C11
Salou 513.6 °C26.7 °C20.3
Castelldefels 513.6 °C26.7 °C19.5
Sitges 513.6 °C26.7 °C13.8
Cartagena 514.9 °C26.6 °C28.5
Vera 514.8 °C26.4 °C13.6
Garrucha 514.8 °C26.4 °C8.3
Mojácar 514.8 °C26.4 °C4.1
Badalona 513.4 °C26.3 °C13.5
Barcelona 513.4 °C26.3 °C17.3
Mataró 513.3 °C26 °C17.9
Blanes 513.3 °C25.8 °C8.9
Lloret de Mar 513.3 °C25.8 °C8.6
Almería 515.1 °C25.4 °C24.9
Roquetas de Mar 515.2 °C25.3 °C15.5
Adra 515.2 °C24.9 °C16.6
Girona 513.3 °C24.7 °C27.7
Salobreña 515.3 °C24.6 °C13.8
Granada 515.3 °C24.6 °C61.5
Almuñécar 515.3 °C24.6 °C13.4
Torre del Mar 515.3 °C24.5 °C13.8
Torrox 515.3 °C24.5 °C14.5
Nerja 515.3 °C24.5 °C14.4
Vélez-Málaga 515.3 °C24.5 °C18
Jerez de la Frontera 515.3 °C23.4 °C23.2
Sanlúcar de Barrameda 515.3 °C23.4 °C17.2
El Puerto de Santa María 515.3 °C23.4 °C13.2
Cádiz 515.3 °C23.4 °C12.9
Seville 515.2 °C23.3 °C80.6
Chiclana de la Frontera 515.5 °C23.1 °C5.4
Conil de la Frontera 515.5 °C23.1 °C12.1
Huelva 515 °C23 °C16.4
Punta Umbría 515 °C23 °C10.3
Isla Cristina 515.5 °C22.2 °C9.6
Ayamonte 515.5 °C22.2 °C10.2
Alhaurín de la Torre 415.2 °C24.3 °C17.5
Málaga 415.2 °C24.3 °C11.5
Mijas 415.2 °C24.3 °C23.6
Rincón de la Victoria 415.2 °C24.3 °C13.6
Benalmádena 415.2 °C24.3 °C13
Torremolinos 415.2 °C24.3 °C11.1
Fuengirola 415.5 °C23.3 °C18.3
Roses 413.2 °C23 °C20.6
Tarifa 416 °C21.9 °C15.4
San Sebastián / Donostia 312.5 °C22.7 °C10.7
Zarautz 312.6 °C22.7 °C10.7
Marbella 315.4 °C22.6 °C15
Castro Urdiales 312.8 °C22.2 °C7.6
Laredo 312.8 °C22.2 °C23.2
Bilbao 312.8 °C22.2 °C19.8
Getxo 312.8 °C22.2 °C10.5
Santander 312.9 °C22.1 °C18.8
Manilva 315.4 °C22.1 °C11.1
Estepona 315.4 °C22.1 °C6.1
Llanes 312.9 °C21.7 °C24.7
Los Barrios 315.5 °C21.5 °C12.6
Algeciras 315.5 °C21.5 °C7.5
La Línea de la Concepción 315.5 °C21.5 °C5.2
San Roque 315.5 °C21.5 °C9.5
Gijón 212.9 °C21.1 °C9.3
Avilés 112.9 °C20.9 °C8.6
Oviedo 112.9 °C20.9 °C29.5
Viveiro 112.9 °C20.2 °C25.9
Ribadeo 013 °C19.9 °C12.6
Narón 013 °C19.3 °C10.7
Carballo 013 °C18.5 °C18.8
Ferrol 013 °C18.4 °C16.4
Sada 013 °C18.4 °C8.5
A Coruña 013 °C18.4 °C3.3
Camariñas 013.2 °C17.8 °C19.1
Fisterra 013.3 °C17.2 °C10.9
Vigo 013.5 °C17 °C18.1
Pontevedra 013.4 °C16.9 °C19.9
Sanxenxo 013.4 °C16.9 °C6
Cee 013.3 °C16.7 °C11.1

How it is built

The source is NOAA's OISST 2.1 daily sea-surface grid at 0.25°, running since September 1981. We take the ten most recent full years, 2015–2024: a normal should describe the sea a person will step into, not a forty-year average.

A town's coordinates sit on land, and the grid is empty over land. So a box is taken around the place, the cells that hold water are kept, and the nearest one is picked. Its distance is a column of its own in the table, so you can see how closely the figure belongs to that shore.

Validation: on 1 August 2024 the coastal gauge off Málaga averaged 25.06 °C across twenty-four hourly readings; the grid gave 25.13 °C for the same day. The difference is 0.07 °C.

What it changes in our base: 132 places used to differ by seventeen profiles, because values were written per coast. There are now 80, and the count of months above 20 °C changed for forty places.

Licence and how to cite

Our compilation is published under CC BY 4.0. The primary source is a United States government dataset, freely distributed; its own terms are at the link below.

Relocoast. Monthly sea temperature on the Spanish coast, 2015–2024. From the NOAA OISST 2.1 daily grid. https://relocoast.com/en/data/sea-temperature

Primary source: the NOAA OISST 2.1 grid

This is an observation, not a forecast: a ten-year monthly normal describes a shore's climate and promises nothing about a particular day.