Traeth Llanddwyn sea temperature
Sea-surface temperature for Traeth Llanddwyn, United Kingdom, with the 7-day outlook and what to wear.
What is the sea temperature at Traeth Llanddwyn today? (19 Oct)
The sea at Traeth Llanddwyn is 14.3 °C today. A 4/3 keeps a two-hour session comfortable; many people add boots. Most people add boots on longer sessions. The sea and the air are within a degree or so of each other.
Traeth Llanddwyn sea temperature — next 7 days
Sea temperature is cooling across the week, by about 1.4 °C from start to end.
| Date | Sea temp | Range | Suggested wetsuit |
|---|---|---|---|
| Mon 19 Octtoday | 14.3 °C14.3–14.4 °C | 14.3–14.4 °C | 4/3 mm full suit |
| Tue 20 Oct | 14.1 °C13.9–14.3 °C | 13.9–14.3 °C | 4/3 mm full suit |
| Wed 21 Oct | 14.0 °C13.8–14.1 °C | 13.8–14.1 °C | 4/3 mm full suit |
| Thu 22 Oct | 13.8 °C13.7–13.8 °C | 13.7–13.8 °C | 5/4 mm full suit |
| Fri 23 Oct | 13.5 °C13.3–13.7 °C | 13.3–13.7 °C | 5/4 mm full suit |
| Sat 24 Oct | 13.1 °C13.0–13.3 °C | 13.0–13.3 °C | 5/4 mm full suit |
| Sun 25 Oct | 13.0 °C12.9–13.0 °C | 12.9–13.0 °C | 5/4 mm full suit |
Figures are modelled sea-surface temperature, not readings from a buoy or a thermometer in the shallows — expect a degree either way, and more in a shallow bay on a hot afternoon. Wetsuit suggestions are general guidance: cold tolerance varies a lot between people, and wind, session length and air temperature matter as much as the water does.
What wetsuit for what sea temperature?
| Sea temperature | Wetsuit | Extras |
|---|---|---|
| 24 °C and above | Boardshorts or swimsuit | — |
| 22–24 °C | Rash vest or 1 mm top | — |
| 19–22 °C | 2 mm shorty or spring suit | — |
| 17–19 °C | 3/2 mm full suit | — |
| 14–17 °CTraeth Llanddwyn today | 4/3 mm full suitboots on longer sessions | boots on longer sessions |
| 11–14 °C | 5/4 mm full suitboots and gloves | boots and gloves |
| 7–11 °C | 5/4/3 mm hooded full suitboots and gloves | boots and gloves |
| Below 7 °C | 6/5 mm hooded full suitthick boots and gloves | thick boots and gloves |
Conditions at Traeth Llanddwyn
Water temperature is one input. For wave height, wind and a 0–100 score per sport and ability level, see the full forecast.
Sea temperature near Traeth Llanddwyn
Frequently asked questions.
What is the sea temperature at Traeth Llanddwyn today?
The sea at Traeth Llanddwyn, United Kingdom is 14.3 °C today. This is modelled sea-surface temperature rather than a buoy reading, so allow a degree either way.
What wetsuit do I need at Traeth Llanddwyn?
At 14.3 °C, 4/3 mm full suit is the usual choice at Traeth Llanddwyn. A 4/3 keeps a two-hour session comfortable; many people add boots. Most people add boots on longer sessions. Cold tolerance varies, and wind and session length matter as much as the water temperature.
Is the sea warm enough to swim at Traeth Llanddwyn?
At 14.3 °C the sea at Traeth Llanddwyn is cold. Short swims only without a wetsuit, and be aware of cold-water shock.
How much does the sea temperature at Traeth Llanddwyn change over a week?
Over the next 7 days the sea at Traeth Llanddwyn stays between 12.9 °C and 14.4 °C. Open water changes temperature slowly, so it rarely moves much inside a week — seasonal change is what matters.
