The Truth About the Rumoured Atlantic Heatwave: Could Lanzarote Be About to Get Much Hotter?
There has been plenty of talk about a possible new heatwave developing around the Canary Islands, with claims that rising Atlantic sea temperatures could push temperatures several degrees higher. But how much truth is there behind the story?
With Lanzarote already experiencing a very warm summer, we decided to look at what the meteorological data actually says.
Yes, the Atlantic really is unusually warm
The first part of the story is absolutely true.
A marine heatwave has been affecting parts of the North Atlantic and surrounding waters during the summer of 2026. According to the latest Copernicus Marine Service bulletin, issued on 22 August, the North Atlantic marine heatwave is currently shrinking in both size and intensity.
However, several areas remain classified as being in the “strong” marine heatwave category — including waters around the Canary Islands.
That means the sea surrounding the islands is significantly warmer than would normally be expected for this time of year.
So where does the “1 to 3 degrees” claim come from?
This is where the story needs a little clarification.
There are areas of the Atlantic where sea-surface temperatures are around 1–3°C above the seasonal average, with some marine heatwave areas considerably higher.
But that doesn’t mean the entire Atlantic is about to suddenly rise by another 3°C, nor does it mean Lanzarote’s air temperature will automatically increase by 3°C.
The figures being discussed are largely referring to sea-temperature anomalies — the difference between the current sea temperature and what would normally be expected.
A sea temperature anomaly of +2°C, for example, does not translate directly into an air temperature anomaly of +2°C.
Can warmer seas actually make a heatwave worse?
Yes.
This is perhaps the most important part of the story for Lanzarote.
The Spanish State Meteorological Agency, AEMET, has already highlighted the effects of unusually warm seas around Spain and the Canary Islands.
The sea acts as a huge heat reservoir. During the day it absorbs heat, and at night it releases it slowly. When the surrounding sea is unusually warm, it becomes less effective at cooling the air.
That can particularly affect night-time temperatures, increasing the likelihood of what are known as tropical nights — when temperatures remain above 20°C.
AEMET says the effects of the current marine heatwave are particularly noticeable in areas including the Canary Islands.
For people living in or visiting Lanzarote, that can mean something very noticeable: hotter, more humid and more uncomfortable nights, even if daytime temperatures don’t suddenly shoot up by several degrees.
Does this mean another heatwave is definitely coming to Lanzarote?
No — and this is where some of the claims circulating online go too far.
At the moment, there is no official forecast saying that Lanzarote is definitely about to experience a 3°C heatwave because the Atlantic is warming.
In fact, the latest Copernicus Marine bulletin says that the North Atlantic marine heatwave is currently weakening overall, although strong areas remain around the Canary Islands.
AEMET’s current forecasts also do not show an immediate extraordinary heat event for the Canary Islands.
That doesn’t mean another heatwave can’t develop. Weather patterns can change, particularly over a period of several weeks.
But there is currently a big difference between “conditions could contribute to another heatwave” and “a 3°C heatwave is on the way.”
Lanzarote is already in an unusually warm environment
There is nevertheless good reason to keep watching the situation.
The Canary Islands have already experienced several significant periods of heat this summer, including a July heatwave when temperatures approached or exceeded 38°C in parts of the archipelago.
And the latest marine data confirms that the waters around the Canary Islands remain one of the strongest remaining marine heatwave areas in the North Atlantic.
So if a suitable atmospheric pattern develops — particularly persistent high pressure, warm air arriving from North Africa or a period of weak winds — the unusually warm sea could help maintain elevated temperatures.
What should Lanzarote residents and visitors watch for?
The important thing over the coming days will be the atmospheric pattern, rather than simply the sea temperature.
If forecasts begin showing a combination of:
- Persistent high pressure
- Very warm air moving north from Africa
- Weakening trade winds
- Increasingly warm nights
- Rising sea-surface temperatures around the islands
- Calima conditions
then the likelihood of a significant heat episode would increase.
For now, however, the evidence suggests “watch this space” rather than “another major heatwave is definitely coming.”
The Atlantic is certainly unusually warm, and the waters around Lanzarote and the other Canary Islands remain affected by a marine heatwave. But the claim that a 1–3°C rise in Atlantic temperatures automatically means a 3°C heatwave for Lanzarote is not supported by the current forecasts.
Sources: Copernicus Marine Service/Mercator Ocean International and Spain’s State Meteorological Agency (AEMET).
