France · Seine-Maritime
Les Grandes-Dalles
Seine-Maritime, France
On the beach
Right now
Sample dataIllustrative conditions — the live Open-Meteo marine feed wasn't reachable, so these are deterministic placeholder values that will be replaced automatically once the feed is available.
7-day outlook
Sample dataModeled placeholder forecast for demonstration — will be replaced by a live marine-weather feed.
Sea temperature
Next 7 days, °C
Wave height
Next 7 days, metres
View as table
| Day | Sea temp (°C) | Wave height (m) |
|---|---|---|
| Wed 2 | 24.8 | 0.4 |
| Thu 3 | 25.0 | 0.4 |
| Fri 4 | 24.9 | 0.4 |
| Sat 5 | 24.4 | 0.4 |
| Sun 6 | 24.0 | 0.4 |
| Mon 7 | 23.9 | 0.4 |
| Tue 8 | 24.2 | 0.4 |
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 | 14 |
| Feb | 14 |
| Mar | 14 |
| Apr | 16 |
| May | 19 |
| Jun | 22 |
| Jul | 24 |
| Aug | 25 |
| Sep | 24 |
| Oct | 22 |
| Nov | 19 |
| Dec | 16 |
Location & nearby beaches
Nearby beaches
- Les Petites-Dalles1.1 kmSeine-Maritime
- St-Pierre-En-Port2.2 kmSeine-Maritime
- Veulettes-Plage7.1 kmSeine-Maritime
- Base de Loisirs Vittefleur Lac de Caniel8.9 kmSeine-Maritime
Distances calculated as straight-line (haversine) from official coordinates.
Getting there & around
- Easy by car — there's parking close to the beach.
Food, stays & town
- Nearest village: Saint-Pierre-en-Port, about ~1.9 km away.
- 1 place to eat within 1 km Closest is Bière à bord, about ~170 m away.
- 1 place to stay mapped nearby Closest is Yourtes pour Apprendre Nature, 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).
- Families
Is the water clean at Les Grandes-Dalles?
Les Grandes-Dalles 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 Seine-Maritime. You can park about ~170 m away.
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. Saint-Pierre-en-Port — the closest town — sits about ~1.9 km from here.
That “Excellent” label comes from a full season of official water sampling, not a single test — it's one step on a four-point scale (Excellent, Good, Sufficient, Poor) reassessed once a year. Today's actual conditions can differ from the seasonal average, so for a live snapshot see the “Right now” and 7-day outlook panels above. It's been a consistently reliable spot too — the rating has held at Excellent for 11 straight years. There's 1 place to eat near the beach — Bière à bord, about ~170 m away.
Frequently asked questions
Can you safely swim at Les Grandes-Dalles?
Generally, yes. Les Grandes-Dalles's 2025 EU Bathing Water rating is Excellent — the highest tier — backed by 11 of 11 classified seasons rated Excellent or Good. It's also held steady at Excellent for 11 straight years.
How cold or warm is the water at Les Grandes-Dalles today?
That's placeholder data, not a live measurement: Les Grandes-Dalles's marine-weather feed couldn't be reached, so the panel above is showing an estimated ~24°C until the real feed comes back. That's the reading right off Seine-Maritime.
Which month has the warmest sea at Les Grandes-Dalles?
July–September is typically the most reliable swimming window, with the sea usually warmest in the second half of summer. That applies to the water around Seine-Maritime.
How is the water quality rating measured?
The grade comes from a full season of official sampling for intestinal enterococci and E. coli, reported to the European Environment Agency each spring under the EU Bathing Water Directive, which assigns Excellent, Good, Sufficient or Poor. Some countries (Croatia, via IZOR) also publish individual in-season samples ahead of that report; Les Grandes-Dalles doesn't have that feed yet.
How do you get to Les Grandes-Dalles?
By car, it's easy — parking is right by the beach. The nearest town is Saint-Pierre-en-Port, about ~1.9 km away.