Sea temperature around Tenerife, month by month

Almost every boat trip in southern Tenerife sells a swim stop, and almost none of them tells you what the water will feel like in February. The island’s reputation for eternal spring is about the air. The Atlantic runs on its own schedule, and it is a slower one.

The figures below are the ten-year monthly averages published by seatemperature.info for Los Cristianos, which calculates them from satellite and in-situ data. They describe a typical month, not your morning.

The twelve months, in the south

Month	Average	Month	Average
January	20.1 °C	July	22.2 °C
February	19.4 °C	August	23.1 °C
March	19.2 °C	September	23.8 °C
April	19.6 °C	October	23.7 °C
May	20.4 °C	November	22.6 °C
June	21.5 °C	December	21.2 °C

The whole year fits into a band of roughly four and a half degrees. There is no month in which the sea off Los Cristianos is cold in the northern European sense, and no month in which it is warm in the Mediterranean-August sense either.

The coldest water is not in January

The obvious mistake is to assume the sea follows the calendar of the air. It does not. On these averages the low point is March, at 19.2 °C, with February and April on either side of it — a full quarter after the shortest day.

The high point is the mirror image: September, at 23.8 °C, with October only a tenth of a degree behind. The ocean stores heat and releases it late, so the best swimming weeks of the year are the ones after the summer school holidays have ended.

For planning, that has two practical consequences. An Easter trip meets the coldest water of the year, not a spring warm-up. And a late-September or October booking gets the warmest sea of the year at a quieter time — which is why the swim stop on a two-hour cruise like the Los Cristianos whale-watching trip is a genuinely different proposition in October than in March.

The north is not colder — the surface is rougher

The intuition that the northern coast has colder water turns out to be wrong. The same source’s ten-year averages for Puerto de la Cruz run 19.9 °C in January, 19.1 °C in March, 23.9 °C in September and 21.1 °C in December — within about three tenths of a degree of the south all year round.

What differs between the coasts is not temperature but exposure: wind, swell and how often the surface is workable. That is why the boat trips cluster in the south and why the north’s swimming culture leans on sheltered pools and bays. If you have read that the north is “colder”, the water is not the reason. Our note on what to see in the north and south explains the rest of that split.

Averages are not guarantees

The same source gives a spread as well as a mean. September averages 23.8 °C but has ranged from about 22.3 °C to 26.2 °C; March averages 19.2 °C with a range from roughly 17.9 °C to 20.8 °C. A specific week can sit a degree or more either side of the table above, and local upwelling along a particular stretch of coast can be cooler than the island figure.

So treat the table as a planning tool, not a forecast. If the exact temperature matters to your booking, ask the operator what people are wearing in the water that week — they are out there daily and have no reason to talk you out of a swim.

What this means for wetsuits and swim stops

Several operators quietly solve the problem for you. The three-hour kayak and snorkelling tour from Los Cristianos lists a wetsuit among its inclusions, and the operator’s own site describes wetsuits as winter equipment. Guided snorkelling and beginner dives generally include a suit as a matter of course; a swim stop on a whale-watching cruise generally does not, because it is a jump off a ladder rather than an hour in the water.

That is the distinction worth carrying into a booking. Twenty minutes bobbing beside a boat at 19 °C is a brisk experience but a short one. Ninety minutes face-down and motionless with a snorkel at the same temperature is a different matter entirely, and it is exactly why the snorkelling operators supply neoprene.

How any individual copes with cooler water — children, older travellers, anyone with a health condition — is not something a comparison page can judge. Ask a pharmacist or your doctor if there is a medical question in the group, and ask the operator whether a wetsuit can be added for your date.

Which months I would pick for what

For swimming and snorkelling, September and October, in that order: warmest water, calmer holiday traffic, and the same trips running. For whale watching, the temperature hardly matters — the pilot whales and dolphins in the Teno-Rasca waters are there all year, and a January cruise sees the same animals as a July one.

For a February or March trip, plan the sea in properly: book the activities that supply a wetsuit, treat the swim stop as optional rather than the point of the outing, and put the budget into a longer boat trip instead. The snorkelling and diving category collects the trips where the equipment is part of the price.