Sea temperature and swimming season in Iquique

The sea off Iquique is comfortable for swimming from January to February. It peaks at 19.2°C in February and drops to 16.6°C in August.

"Warm enough" is a judgement, not a fact

There is no objective temperature at which the sea becomes swimmable. A Norwegian and a Spaniard will disagree, and neither is wrong. The season above uses 19.0°C — the bottom of the range most people describe as comfortable in swimwear — but here is what other thresholds imply:

If you are	Minimum	Months you can swim
Hardy	16.0°C	12 of 12
Most people	19.0°C	2 of 12
Prefer it warm	22.0°C	none
Prefer it hot	25.0°C	none

Month by month

Sea temperature, the air you climb out into, and the wind that decides how that feels.

Sea temperature, air temperature, wind and daylight by month.
Month	Sea	Air	Wind	Feels	What to wear
January	19.2°C	25.5°C	2.0 m/s	Comfortable	shorty, or nothing if you are acclimatised
February	19.2°C	25.0°C	2.0 m/s	Comfortable	shorty, or nothing if you are acclimatised
March	18.9°C	23.4°C	2.2 m/s	Bracing	shorty, or nothing if you are acclimatised
April	18.5°C	23.2°C	1.9 m/s	Bracing	shorty, or nothing if you are acclimatised
May	18.0°C	20.8°C	2.0 m/s	Bracing	3/2 mm full suit
June	17.9°C	20.9°C	2.0 m/s	Bracing	3/2 mm full suit
July	16.8°C	18.6°C	1.8 m/s	Bracing	3/2 mm full suit
August	16.6°C	19.9°C	2.0 m/s	Bracing	3/2 mm full suit
September	16.7°C	19.7°C	2.2 m/s	Bracing	3/2 mm full suit
October	17.0°C	20.4°C	2.2 m/s	Bracing	3/2 mm full suit
November	17.7°C	21.3°C	2.0 m/s	Bracing	3/2 mm full suit
December	18.9°C	23.0°C	2.1 m/s	Bracing	shorty, or nothing if you are acclimatised

Air is the average daily maximum — roughly what you would meet swimming in the middle of the day. An arrow marks months where the air is colder than the sea.

When in the day can you swim?

Daylight and burn risk by month, in America/Santiago local time.

Month	Sunrise	Sunset	Daylight	Peak UV
January	07:13	20:26	13h 13m	14.4
February	07:32	20:17	12h 45m	14.4
March	07:43	19:55	12h 13m	13.2
April	06:51	18:29	11h 38m	10.6
May	07:02	18:11	11h 09m	8.1
June	07:13	18:08	10h 55m	6.9
July	07:16	18:17	11h 01m	7.3
August	07:02	18:27	11h 26m	9.1
September	07:36	19:35	11h 59m	11.6
October	07:09	19:42	12h 33m	13.4
November	06:52	19:57	13h 04m	14.1
December	06:55	20:16	13h 21m	14.1

Open water burns faster than a beach: the surface reflects sunlight up at you, and sunscreen washes off in the first few minutes. A long swim under a UV index above 6 needs a rash vest more than it needs more cream.

What the bands mean

From	Description	In practice
above 26°C	Bath-like	Warm enough that it offers no cooling at all
above 22°C	Very comfortable	Swimwear, no time limit for most people
above 19°C	Comfortable	Pleasant once you are in; most people swim happily
above 16°C	Bracing	Swimmable but short; many prefer a shorty wetsuit
above 12°C	Cold	Wetsuit territory. Unprotected swims should be brief
below 12°C	Dangerous	Cold shock risk. Specialist gear and supervision

Do you need a wetsuit in Iquique?

Some months, yes. The sea drops to 16.6°C in August. What thickness, month by month, for swimming and for surfing →

Other coastal cities in Chile

Where these numbers come from, and what they miss

Open water, not your beach. The measurement is a satellite cell about 28 km across, centred 10.2 km from Iquique. Shallow bays and lagoons run warmer; exposed coasts with upwelling run colder, sometimes by several degrees.
Surface temperature. Below a few metres the sea is often noticeably colder, and in summer a warm surface layer can sit over much colder water.
A six-year average, not a thirty-year normal. Sea temperature varies little between years, so this is close — but it is not a climate normal, and any individual year will differ.
Averages hide storms. A monthly mean says nothing about the week a cold current arrives.

Full methodology, sources and known limitations