France · Loire-Atlantique
Sea temperature at Pors-Er-Ster
Pleasant for swimming
Updated hourly from the live marine forecast. See the 12-month typical range and, where available, real measured readings further down the page.
7-day outlook
7-day sea temperature forecast from Open-Meteo, refreshed hourly.
Sea temperature
Next 7 days, °C
View as table
| Day | Sea temp (°C) |
|---|---|
| Wed 2 | 21.2 |
| Thu 3 | 21.4 |
| Fri 4 | 21.5 |
| Sat 5 | 22.4 |
| Sun 6 | 21.8 |
| Mon 7 | 21.9 |
| Tue 8 | 21.7 |
Sea temperature by month
Modeled climatology derived from latitude and season.
Typical vs. measured sea temperature
12-month view, °C — modeled line vs. measured sample averages
View as table
| Month | Modeled (°C) | Measured avg. (°C) |
|---|---|---|
| Jan | 15 | — |
| Feb | 14 | — |
| Mar | 15 | — |
| Apr | 17 | — |
| May | 19 | — |
| Jun | 22 | — |
| Jul | 23 | — |
| Aug | 24 | — |
| Sep | 24 | — |
| Oct | 22 | — |
| Nov | 20 | — |
| Dec | 17 | — |
No measured in-season sea temperature has been published for Pors-Er-Ster yet — the chart above shows the modeled climatology only. Some countries (Croatia, via IZOR) also record the sea temperature at each official water sample; check the water quality page for this beach's sampling status.
Frequently asked questions
How warm is the sea at Pors-Er-Ster right now?
Pors-Er-Ster's sea temperature is currently around 21°C, based on the most recent hourly reading. See the 7-day chart above for the short-term trend and the monthly chart further down for the seasonal typical. That's the reading right off Loire-Atlantique.
What's the best month to visit Pors-Er-Ster for swimming?
Aim for July–September — the modeled water temperature typically clears 22°C in that window, the rule of thumb for comfortably warm swimming, with August usually the peak. That applies to the water around Loire-Atlantique.
Is the sea temperature chart above measured or estimated?
Not currently for Pors-Er-Ster — the chart above is a modeled estimate based on latitude and season rather than a measured average. A few countries (Croatia, via IZOR) do publish the sea temperature taken at each official water sample, and that's plotted alongside the modeled curve when it exists.