Photo: Florida Memory · Public domain
openwatertemperature.com · 1,740 measured sea and lake spots, today

Wetsuit or skin? The water decides.

For open water swimmers the temperature is not trivia: it decides wetsuit, exposure time and safety. Whipray Basin measures 33.0 °C, Nigardsbrevatn 3.9. Every spot here is a real buoy, gauge or agency station. Rivers stay on their own pages; this is sea and lake.

33.0 °C
warmest · Whipray Basin
3.9 °C
coldest · Nigardsbrevatn
184
spots below 14 °C
1,251
spots at 18 °C or more
The wetsuit gauge

Every spot, sorted by what it asks of you

The bands most federations use: below 14 °C races mandate neoprene, below 18 °C most swimmers choose it, above 22 °C it comes off. The bars show how many measured spots sit in each band this morning.

below 10 °CSkin, if you know what you do
20
10–14 °CWetsuit mandatory in races
164
14–18 °CWetsuit advised
305
18–22 °CWetsuit optional
353
22 °C and upSkin swim
898
Where the numbers come from

Buoys, gauges, agencies, never a model

NOAA buoys and tide stations, the estuary reserves, European hydrographic services, national bathing-water networks: every spot on this page is a physical station with a measurement time. The Open-Meteo model points we carry for coasts without a station are deliberately not here; they live on the country pages with a model label.

NOAA NDBCNOAA CO-OPSNERRSBAFUISPRA+ 60 more networks
Cold water shock

The involuntary gasp in the first sixty to ninety seconds is what drowns strong swimmers. Enter slowly, breathe out long, wait until it settles, then swim. Acclimatise over weeks, not minutes. Below 10 °C, count minutes and get out warm, not cold.

Good to know
At what temperature do I need a wetsuit?

Common guidance: below ~18°C most swimmers choose neoprene, below ~14°C it is strongly advised, and races often mandate it. The free BrrChecker app gives a per-sport call for every measured spot.

What is cold water shock?

The involuntary gasp reflex in roughly the first 60–90 seconds in cold water. Enter slowly, control your breathing before swimming — and never swim alone in cold water.

Where do these values come from?

Official buoys, gauges and agency networks — measured, timestamped, never modelled. Right now the warmest measured open water in our network is Whipray Basin at 33.0 °C.

Measure first, then decide.

Per-sport verdict for every measured spot, plus alerts when your spot crosses your threshold, free in the app.

Download on the App Store