France · Loire-Atlantique
Portmain
Loire-Atlantique, France
On the beach
Right now
Live conditions from Open-Meteo, refreshed hourly.
7-day outlook
7-day marine forecast from Open-Meteo.
Sea temperature
Next 7 days, °C
Wave height
Next 7 days, metres
View as table
| Day | Sea temp (°C) | Wave height (m) |
|---|---|---|
| Wed 2 | 21.7 | 0.4 |
| Thu 3 | 21.8 | 0.5 |
| Fri 4 | 22.0 | 0.5 |
| Sat 5 | 22.8 | 0.5 |
| Sun 6 | 22.5 | 0.7 |
| Mon 7 | 22.6 | 0.7 |
| Tue 8 | 22.4 | 1.0 |
Water quality history
Official EEA classification, one rating per bathing season, 2015–2025 — real data reported by national authorities.
- 2015: Excellent2015
- 2016: Excellent2016
- 2017: Excellent2017
- 2018: Excellent2018
- 2019: Excellent2019
- 2020: Good2020
- 2021: Good2021
- 2022: Good2022
- 2023: Good2023
- 2024: Excellent2024
- 2025: Excellent2025
Excellent in the most recent season, and 11 of 11 classified years rated Excellent or Good.
- Excellent
- Good
- Sufficient
- Poor
- Not classified
View as table
| Year | Classification |
|---|---|
| 2015 | Excellent |
| 2016 | Excellent |
| 2017 | Excellent |
| 2018 | Excellent |
| 2019 | Excellent |
| 2020 | Good |
| 2021 | Good |
| 2022 | Good |
| 2023 | Good |
| 2024 | Excellent |
| 2025 | Excellent |
Typical sea temperature by month
Modeled estimatePlausible seasonal climatology derived from latitude, for illustration — not a measured average.
Monthly sea temperature
Typical range across the year, °C
View as table
| Month | Typical sea temp (°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 |
Location & nearby beaches
Nearby beaches
- L'Etang905 mLoire-Atlantique
- Plage Du Choizeau1.4 kmLoire-Atlantique
- Le Porteau1.5 kmLoire-Atlantique
- Les Sablons2.2 kmLoire-Atlantique
Distances calculated as straight-line (haversine) from official coordinates.
Getting there & around
- Easy by car — there's parking close to the beach.
- Bus stop: Saint Marie de la Mer /Le Portmain (S), about ~540 m away.
Food, stays & town
- Nearest village: Sainte-Marie-sur-Mer, about ~2.6 km away.
- 1 place to eat within 1 km Closest is La Papagayo, about ~20 m away.
What kind of beach is this?
With no facilities mapped nearby, this beach is usually on the quiet side even in season — worth knowing if you're after solitude, but also worth bringing your own water and shade.
Estimated from OpenStreetMap surroundings data (ODbL).
- A quiet swim
Is the water clean at Portmain?
Thinking of swimming at Portmain? The short answer: its official EU Bathing Water rating for 2025 is Excellent — the highest official classification under the EU bathing-water assessment. That rating is set once a year under the EU Bathing Water Directive, from a full season of testing for intestinal enterococci and E. coli reported to the European Environment Agency the following spring, so the 2025 season's grade appeared in spring 2026 and the 2026 season won't be graded until spring 2027. In addition to that yearly rating, some national authorities — for Croatia, the national environmental authority — publish individual water sample results during the season itself, ahead of the annual report. It's been a consistently reliable spot too — the rating has held at Excellent for 2 straight years. There's parking about ~40 m from the beach.
Looking to avoid the busiest weeks? The water is typically warmest around August, with the most reliable swimming window running July–September; outside that stretch you'll find a cooler sea but a quieter beach. That rating has been consistent: every one of the 11 classified seasons on record has come back Excellent or Good. On site you'll find Sandy shore, Toilets, and Beach bar. The nearest town, Sainte-Marie-sur-Mer, is about ~2.6 km away.
Worth remembering: “Excellent” isn't a live reading, it's an annual grade — Excellent, Good, Sufficient or Poor — set once a year from that season's water samples and describing the average, not this afternoon's conditions. For what the sea is doing right now, check the “Right now” panel and 7-day outlook above. It sits in Loire-Atlantique. There's 1 place to eat near the beach — La Papagayo, about ~20 m away.
Frequently asked questions
Is it safe to go in the water at Portmain?
Yes, without much reservation. Portmain holds the top EU Bathing Water classification, Excellent, for 2025, and 11 of 11 classified seasons here have rated Excellent or Good. It's also held steady at Excellent for 2 straight years.
What's the current water temperature at Portmain?
Portmain's sea temperature currently sits at around 21°C, based on the latest update — check the “Right now” panel above for the full live picture. That's the reading right off Loire-Atlantique. On the modeled climatology here, August usually runs warmest.
When does Portmain have the warmest water?
For swimming, July–September is usually the best call — that's the modeled window when the sea here runs warmest. That applies to the water around Loire-Atlantique. Within that window, August is typically the single warmest month.
How is bathing water quality actually assessed?
It's based on official water samples: authorities test for intestinal enterococci and E. coli through the season, then report the full-season results to the European Environment Agency each spring, which assigns one of four grades — Excellent, Good, Sufficient or Poor. A few national authorities, including Croatia's IZOR, also publish individual samples during the season itself, ahead of that annual report — that isn't yet available for Portmain.
What's nearby Portmain — parking, buses, or a ferry?
By car, it's easy — parking is right by the beach. By bus, the nearest stop is Saint Marie de la Mer /Le Portmain (S), about ~540 m away. The nearest town is Sainte-Marie-sur-Mer, about ~2.6 km away.