Canary Islands microclimates: why the weather changes in 20 kilometres
You book a week in Puerto de la Cruz in January because these are the Canaries, and the Canaries mean sunshine. You arrive, and you spend six days under a grey lid while someone phones you from Costa Adeje, an hour and a half away by car, to say they are sitting outside in short sleeves.
That was not bad luck. That was a microclimate, and it was predictable.
On these islands the weather is not decided by island. It is decided by slope, altitude and which way you face. Two towns twenty kilometres apart can have genuinely different climates, not a difference of nuance. This guide explains why, using measured data, and what to expect depending on where you sleep. If you have not picked an island yet, start with the guide to which Canary Island to choose; for the general season-by-season forecast, see the complete guide to the weather in the Canaries.
What drives it all: the trade wind inversion
Almost every day of the year the trade wind blows over the Canaries: a steady north-easterly that arrives loaded with Atlantic moisture. Above it, air from the Azores high sinks and warms. Where the two meet, a sharp boundary forms: cool damp air below, warm dry air above. That is the trade wind inversion, and it works like a lid.
That lid usually sits between 1,000 and 1,500 metres, according to the radiosonde study of Tenerife by J. J. Bustos and C. Marrero of the Western Canaries meteorological centre. The clouds the trade wind carries hit the northern slopes, rise, and get trapped under the lid. They cannot grow upwards. They flatten out and stay.
Here is the detail almost nobody mentions, and it explains everything: the inversion sits lower in summer and higher in winter. In summer it is also nearly permanent. That is why the north turns grey exactly when the rest of Europe expects the Canaries to be at their best, and why the real rain comes in winter, when the lid lifts and Atlantic fronts break through it.
In practice: in the north, summer brings low cloud without rain, and winter brings scattered sunshine with genuinely wet days.
The numbers, unvarnished
These are AEMET standard climate values for 1981-2010. Four stations, two islands.
Tenerife Norte Airport (632 m, in the La Laguna area): annual mean 16.8 °C, 520 mm of rain a year, 73 % humidity. January: 80 mm and 150 hours of sunshine. July: 6 mm and 262 hours.
Tenerife Sur Airport (64 m, Granadilla): annual mean 21.4 °C, 132 mm a year, 66 % humidity. January: 17 mm and 193 hours. July: 0 mm and 295 hours.
Santa Cruz de Tenerife (36 m): annual mean 21.5 °C, 226 mm a year, 63 % humidity. January: 32 mm and 178 hours. July: 0 mm and 337 hours.
Gran Canaria Airport (24 m, Ingenio): annual mean 21.1 °C, 151 mm a year, 66 % humidity. January: 25 mm and 184 hours. July: 0 mm and 308 hours.
Read the first line against the second again: four and a half degrees of annual mean, and four times the rainfall, on the same island, sixty kilometres apart.
And now the surprise, because data does not always say what you expect: in July, Santa Cruz gets more sunshine hours than the southern airport. Santa Cruz sits sheltered behind the Anaga massif, which cuts off the trade wind cloud. The capital is neither the damp north nor the touristy south. It is its own case.
An honest warning about these figures. The northern airport is at 632 metres, which puts it inside the band where the cloud lives. It describes the mid-altitude belt very well, but it is not Puerto de la Cruz, which sits at sea level and gets considerably more sun and less rain than those 520 mm. We say so because we checked whether AEMET publishes standard values for the Puerto de la Cruz station and for Las Palmas-Plaza de la Feria: it does not. We would rather tell you where each number comes from than fill the gap with a tidy figure.
Panza de burro, explained
In Las Palmas de Gran Canaria they have their own name for this: panza de burro, the donkey's belly. It is the grey, low, even layer of stratocumulus that settles over the city and the north coast for much of the summer. The name is accurate: from below you see a grey belly that never moves.
It is not bad weather. It does not rain. The temperature stays flat and pleasant, around 22-24 degrees, while mainland Spain melts. To live in, it is a blessing, and it is why Las Palmas boasts about its climate. For a two-week holiday with a suitcase full of swimwear, it can be a let-down if nobody warned you.
Orientation is the key: the donkey's belly clings to the north and north-east. Cross the ridge to the south of the island and you leave it behind.
The sea of clouds: the same cloud, seen from above
Climb above those 1,000-1,500 metres and you pass through the layer and come out on top. Below you a white blanket stretches to the horizon: the mar de nubes, the sea of clouds. Same phenomenon, seen from the other side.
That is why you can leave La Orotava under cloud and reach Teide in burning sunshine, and why the sky above Teide is so good for stargazing: the cloud stays below and acts as a blanket against the light pollution of the coast. The guide to where to see the stars in the Canaries covers that well.
Did you know? That sea of clouds is what keeps the laurisilva alive, the fog forest that covered southern Europe before the ice ages and survived here. The trees do not drink rain: they comb the mist with their leaves and the water drips to the ground. It is called horizontal rain, and in parts of Anaga it delivers more water to the soil than ordinary rainfall does.
Tenerife: what to expect depending on where you sleep
This is the island where the contrast is fiercest, because Teide splits the sky in two.
North (Puerto de la Cruz, La Orotava, Icod)
Green, in flower all year, with towns that have a real historic centre. The trade-off: more cloud, more humidity and grey days spread across the whole year. In winter it genuinely rains. It is the best base if you came to walk, to eat and to see towns, and the worst if your plan is seven days flat on a sunbed. The guachinches of this mid-altitude belt are part of the reason to come anyway: they are listed by area in the guide to the guachinches of Tenerife by area.
The metropolitan area (Santa Cruz, La Laguna)
Two cities fifteen minutes apart with different climates. Santa Cruz, at sea level and sheltered by Anaga, is dry and sunny. La Laguna, at 550 metres, is cool, windy and often foggy. Locals say the weather up there is simply "different", and the measurements agree. When in doubt, check the altitude before the map.
South (Costa Adeje, Los Cristianos, El Médano)
This is where the sunshine hours are and the rain is close to zero. It is the place if you came for the beach with guarantees, especially between November and March. The local nuance: El Médano is windy almost always, which is why it is a world windsurf and kitesurf destination. That counts for or against depending on what you want, but it is not a fluke of the day you turned up. To choose sand, see the best beaches in Tenerife.
Gran Canaria: a continent in miniature
The nickname is earned. Within a few kilometres you go from permanent cloud to sand dune.
Las Palmas and the north-east
Mild, stable weather all year, donkey's belly in summer, and an urban beach, Las Canteras, protected by a natural rock bar. A good city to live in. To guarantee postcard sunshine in August, it is not your first choice.
South (Maspalomas, Playa del Inglés, Mogán)
The other extreme: very reliable sun, minimal rain, high temperatures. It is the classic tourist south for a meteorological reason, not a marketing one. Beaches in the best beaches in Gran Canaria.
Summit and mid-altitudes (Tejeda, Artenara, Valleseco)
The surprise for nearly everyone: in winter it is genuinely cold, and some years it snows on the summit. If you drive up to Roque Nublo in January, take a coat even if you left the beach in a t-shirt. More ideas in the guide to what to see in Gran Canaria.
If you are moving here, not just holidaying
The criteria change completely, and this is the part almost no guide covers.
Humidity is the deciding factor, not temperature. The figures above show it: 73 % mean humidity in the high northern belt against 63 % in Santa Cruz. Ten points are noticeable every single day, in your clothes, your books and your walls.
Damp and mould are a real issue in the north and the mid-altitudes. North-facing houses, little direct sun and high humidity: air the place daily even when it is cool, and think about a dehumidifier before the stain appears, not after.
Houses here have no heating. They almost never need it, but in January, at 600 metres and with high humidity, a house with no sun gets cold inside. When you view a property, ask which way it faces and what time the sun reaches it. That matters more than the square metres.
Altitude counts for more than distance. Three hundred metres of elevation change the climate more than thirty kilometres of road. Before you go to see a house, look up its altitude on the map.
If the plan is to work remotely from here, the practical side (coverage, coworking, paperwork) is in the island-by-island guide for digital nomads.
How to choose and get it right
Decide what you are going to do first, not which island sounds nicest. Guaranteed winter beach: south. Walking, eating, town-hopping: north. City with sunshine: Santa Cruz or Las Palmas.
Check the altitude of your accommodation, not just the name of the municipality. Many northern municipalities run from the sea up to 1,000 metres; the same name can mean two climates.
Count on a car for crossing over. Staying in the north does not condemn you to grey: in an hour and a half you are in the sun. Keeping the north for cloudy days and the south for the rest works very well. How to get around: the guide to car hire and ferries between islands.
In summer, do not judge the north by rainfall. It is not going to rain. It is going to be grey, which is not the same thing, and it is fixed by driving twenty minutes uphill or half an hour south.
In winter, check the forecast the same morning. It is the genuinely variable season, the only one where a front changes the plan on both sides of the island at once.
In the end, what makes these islands special is exactly what ruins the week of anyone who did not know: that in a single morning you can have breakfast under a cloud, lunch above the sea of clouds and dinner in short sleeves facing the Atlantic. The weather here is not unpredictable. There are simply several weathers at once, and all you have to do is know which one you want to wake up in.
Sources
AEMET, Standard climate values 1981-2010 (Tenerife Norte Airport, Tenerife Sur Airport, Santa Cruz de Tenerife and Gran Canaria Airport stations): https://www.aemet.es/es/serviciosclimaticos/datosclimatologicos/valoresclimatologicos
J. J. Bustos and C. Marrero, La inversión del alisio como factor determinante de la meteorología en Canarias, Centro Meteorológico Territorial en Canarias Occidental: https://www.divulgameteo.es/archivos/articulos/meteoroteca/Inversion-alisio-Canarias.pdf