Warm sea

Where is the sea actually warm?

Same air-temperature band as the warm list, plus a sea of at least 22 °C. That single condition removes the Canaries, Madeira and Cape Town for most of the northern winter: all three are pleasantly warm and none of them are swimming.

Right now · September

Ranked for this month

6 destinations in July

Malta

MaltaStrong match

30.7 °C by day and 2 mm of rain. About as good as this month gets.

Central Mediterranean, warm and dry from June to October, and routinely mis-sold as winter sun.

Sea
25.2 °C
Day
30.7 °C
Rain
2 mm

COZZO SPADARO, 103 km away · Malta Met Office / WMO CLINO · 1991–2020 · 14 of 30 years · Checked 2026-08-12

Crete

GreeceStrong match

29.3 °C by day and 1 mm of rain. About as good as this month gets.

The southernmost of the big Greek islands, with a swimming season that runs a month longer at both ends.

Sea
24.8 °C
Day
29.3 °C
Rain
1 mm

HERAKLION · HNMS / WMO CLINO · 1991–2020 · 11 of 30 years · Checked 2026-08-12

Dalmatia

CroatiaStrong match

31 °C by day and 24 mm of rain. About as good as this month gets.

The Adriatic coast: a short, reliable summer and a sea that stays warm well into September.

Sea
24.2 °C
Day
31 °C
Rain
24 mm

SPLIT MARJAN · DHMZ / WMO CLINO · 1991–2020 · Checked 2026-08-12

Canary Islands

SpainStrong match

28.8 °C by day and 0 mm of rain. About as good as this month gets.

Subtropical Atlantic, 100 km off the Sahara: warm every month of the year, and washed by a current that never warms up with it.

Sea
22.2 °C
Day
28.8 °C
Rain
0 mm

STA. CRUZ DE TENERIFE · AEMET · 1991–2020 · Checked 2026-08-12

Madeira

PortugalStrong match

25.2 °C by day — warm, without being the warmest thing on the list.

An Atlantic island with almost no seasons: the difference between its coolest and warmest month is under 8 °C.

Sea
22.1 °C
Day
25.2 °C

FUNCHAL/S.CATARINA · IPMA · 1991–2020 · 19 of 30 years · Checked 2026-08-12

Costa del Sol

SpainStrong match

The air is fine at 31 °C. The sea is 21.9 °C, which is not a swim.

Mainland Spain's warmest winter coast — mild rather than hot, and a genuinely cold sea until June.

Sea
21.9 °C
Day
31 °C
Rain
0 mm
  • Cold sea

    The water is below 22 °C, the point most northern-European swimmers stop calling it swimming. Fine for a walk on the beach; a shock in it.

MALAGA AEROPUERTO · AEMET · 1991–2020 · Checked 2026-08-12

We show at most two places per country so one country cannot fill the list.

How this list is made

A ranking that will not show its criteria is an opinion. These are ours.

Warm days mean a mean daily maximum of 25–33 °C, scoring nothing below 20 °C or above 36 °C. The upper bound is not a formality: Dubai in July is 41 °C, and a list that treats hotter as better puts it first.

Swimmable means a sea of at least 22 °C. There is no meteorological standard for this — it is the convention northern-European travel publishers use, and we are telling you so rather than implying otherwise.

The criteria multiply rather than add, so a perfect air temperature cannot compensate for a cold sea. That is the whole reason the warm list and the swimming list are two separate lists.

Snow reliability is classified against the 100-day rule (Abegg 1996, after Föhn 1990): snow-reliable means at least 30 cm of cover on at least 100 days between 1 December and 15 April, in seven winters out of ten, with the line at about 1,200 m in the Swiss Alps. We classify against that rule and cite it; we do not compute it, because no free dataset carries per-resort snow depth.

Aurora is ranked on corrected geomagnetic latitude, not geographic latitude, and on median winter cloud. The oval sits at roughly 65–70° geomagnetic and moves about 2° equatorward per unit of Kp.

Tropical-cyclone seasons are applied separately from rainfall. A peak month is excluded outright; a shoulder month is capped no matter how dry it is.

Temperature and rainfall are 1991–2020 monthly normals computed from NOAA's Global Historical Climatology Network station records — the station used for each destination is named on its card, along with how far away it is. Sea-surface temperature comes from NOAA OISST v2.1 over the same period. Rain days count days with at least 2.5 mm.

These are thirty-year averages, not a forecast. They tell you what a month is usually like, never what next Tuesday will be.

Sources

Questions

About these lists

Almost always the sea. The Canaries in January are 21 °C in the air and 19 °C in the water — a genuine answer to "somewhere warm" and a bad answer to "somewhere I can swim". Rather than pick one meaning and be wrong for half of you, we run two lists.

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