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 | 22.3 | 0.2 |
| Thu 3 | 22.7 | 0.2 |
| Fri 4 | 22.7 | 0.2 |
| Sat 5 | 22.3 | 0.2 |
| Sun 6 | 21.8 | 0.2 |
| Mon 7 | 21.6 | 0.2 |
| Tue 8 | 21.8 | 0.2 |
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 | 16 |
| Feb | 16 |
| Mar | 17 |
| Apr | 19 |
| May | 21 |
| Jun | 24 |
| Jul | 26 |
| Aug | 27 |
| Sep | 26 |
| Oct | 24 |
| Nov | 21 |
| Dec | 18 |
Location & nearby beaches
Nearby beaches
- Megali Potamia458 mSouth Aegean
- Sxoinari Loutron1.9 kmSouth Aegean
- Limani Loutron2.3 kmSouth Aegean
- Apokrisi7.2 kmSouth Aegean
Distances calculated as straight-line (haversine) from official coordinates.
Getting there & around
- By car: there's parking about ~1.5 km from the beach.
- Ferry: Σέριφος, about ~2.0 km away.
Food, stays & town
- Nearest village: Λιβάδι, about ~2.2 km away.
- 1 place to stay mapped nearby Closest is Isalos, about ~1.4 km 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 Agios Sostis?
Agios Sostis is a coastal bathing site with an official EU Bathing Water rating of Excellent for the 2025 season — the highest official classification under the EU bathing-water assessment. That annual classification comes from the EU Bathing Water Directive: national authorities test for two indicator bacteria, intestinal enterococci and E. coli, throughout the bathing season, then report the full-season results to the European Environment Agency (EEA) the following spring — the 2025 season's rating was published in spring 2026, and the 2026 season won't be rated 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. You can park about ~1.5 km 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. Λιβάδι — the closest town — sits about ~2.2 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.
Frequently asked questions
Can you safely swim at Agios Sostis?
Generally, yes. Agios Sostis'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 warm is the sea at Agios Sostis right now?
That reading, around 22°C, is a placeholder rather than a live measurement, shown only because the marine-weather feed was temporarily unreachable; it updates automatically once the feed returns. That's the reading right off South Aegean.
What's the best month to visit Agios Sostis for swimming?
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 South Aegean.
What does the water quality rating actually measure?
National authorities sample the water for intestinal enterococci and E. coli bacteria through the bathing season and report the full-season results to the European Environment Agency each spring for the season just finished, which assigns one of four annual classifications — Excellent, Good, Sufficient or Poor — under the EU Bathing Water Directive. Some national authorities, including Croatia's IZOR, also publish individual in-season sample results ahead of that annual report.
Can you drive to Agios Sostis?
By car, there's parking about ~1.5 km from the beach. By ferry, the nearest landing is Σέριφος, about ~2.0 km away. The nearest town is Λιβάδι, about ~2.2 km away.