France · Loire-Atlantique
Les Grandes Vallees
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: Excellent2020
- 2021: Excellent2021
- 2022: Excellent2022
- 2023: Excellent2023
- 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 | Excellent |
| 2021 | Excellent |
| 2022 | Excellent |
| 2023 | Excellent |
| 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
- Montbeau467 mLoire-Atlantique
- La Noeveillard541 mLoire-Atlantique
- Les Sablons1.0 kmLoire-Atlantique
- Le Porteau1.8 kmLoire-Atlantique
Distances calculated as straight-line (haversine) from official coordinates.
Getting there & around
- By car: there's parking about ~390 m from the beach.
- Bus stop: Sainte-Marie Place de la Marne, about ~600 m away.
Food, stays & town
- Nearest village: Sainte-Marie-sur-Mer, about ~600 m away.
- 1 place to eat within 1 km Closest is Le Zagaya, about ~30 m away.
- 1 place to stay mapped nearby Closest is Camping du Golf, about ~930 m away.
- 1 shop nearby, about ~1.4 km away
What kind of beach is this?
This beach belongs to a small coastal village. It's usually calmer than a resort or town beach, though a popular village spot can still fill up on the best summer days.
Estimated from OpenStreetMap surroundings data (ODbL).
Is the water clean at Les Grandes Vallees?
Les Grandes Vallees sits on a stretch of coast classed as a coastal bathing site, carrying an official EU Bathing Water rating of Excellent for the 2025 season. Under the EU Bathing Water Directive, national authorities test for intestinal enterococci and E. coli through the season and report the results the following spring — the 2025 rating was published in spring 2026, and 2026's won't follow 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 sits in Loire-Atlantique. There's parking about ~390 m from the beach.
That rating has been consistent: every one of the 11 classified seasons on record has come back Excellent or Good. If you're timing a visit around water temperature rather than crowds, July–September is the safest bet, with August typically the peak — expect a cooler, calmer sea either side of that stretch. The nearest town, Sainte-Marie-sur-Mer, is about ~600 m away.
“Excellent” is one point on a four-step scale — Excellent, Good, Sufficient or Poor — assigned once per year from that season's water samples, not a live reading. It describes how the site performs on average across the season, not the exact water quality this afternoon; for day-to-day sea conditions, see the “Right now” and 7-day outlook panels above. There's 1 place to eat near the beach — Le Zagaya, about ~30 m away.
Frequently asked questions
Should you swim at Les Grandes Vallees?
Les Grandes Vallees is rated Excellent for 2025 — the top EU Bathing Water classification — with 11 of 11 classified seasons rating Excellent or Good, so yes. It's also held steady at Excellent for 11 straight years.
What's the current water temperature at Les Grandes Vallees?
The latest reading puts the sea at Les Grandes Vallees at around 21°C — the “Right now” panel above has the full live picture. That's the reading right off Loire-Atlantique. On the modeled climatology here, August usually runs warmest.
When should you plan a swimming trip to Les Grandes Vallees?
For the warmest water, aim for July–September — that's when the modeled sea temperature is typically at its best. That applies to the water around Loire-Atlantique. Within that window, August is typically the single warmest month.
Where does the water quality rating come from?
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 Les Grandes Vallees.
Is there parking near Les Grandes Vallees?
By car, there's parking about ~390 m from the beach. By bus, the nearest stop is Sainte-Marie Place de la Marne, about ~600 m away. The nearest town is Sainte-Marie-sur-Mer, about ~600 m away.