Portarthur, Derrybeg
Good to go
No current pollution alerts — always assess conditions yourself.
Checked against the Environmental Protection Agency (Ireland) · data last changed 2 months ago.
Sea conditions
Water temperature
14.0°C
Chilly — most swimmers want a wetsuit
Wave height
1.5 m
Significant wave height offshore; inshore conditions vary.
Tide
Going out
- Low water around UTC
- High water around UTC
Modelled values, not measurements — coastal water often differs from the open-sea model, and tide times are approximate to within about half an hour. Use official tide tables for anything that depends on precise timing.
About this spot
Portarthur beach is a north facing, long sandy beach; confined by a rocky outcrop east of Inishmeane Island to the North and a small estuary to the south. Fixed dunes are frequent throughout the site. They support a wide variety of plant species including some rare plant forms. There are also a wide range of bird species. Portarthur is situated in a Gaeltacht area with a variety of islands off the coast. Activities at Portarthur beach include swimming, kayaking, boating, sailing, power boating, jet skiing, diving and other land based activities on the beach. The designated bathing area is approx. 0.225km2 and the extent along the water is approximately is 1070m. There is a deep gradient off Portarthur Beach with the water depth reaching 1m approx. 10m from the water line and continuing out at a deep slope.
This spot’s record
Portarthur, Derrybeg is in Donegal, about 14 km from Falcarragh. Portarthur, Derrybeg was rated Excellent in 2025 by the Environmental Protection Agency (Ireland). Its previous classifications were Excellent in 2024, Excellent in 2023 and Good in 2022, so the rating here has moved rather than held. In the previous bathing season Portarthur, Derrybeg was under a short-term pollution restriction on 10 days. That is last season's record and not a forecast for today. Across the 12 most recent samples published by the Environmental Protection Agency (Ireland), E. coli counts ranged from 10 to 644 per 100 ml. The highest was taken on 23 June 2025. A classification is calculated from percentiles across four seasons, so no single reading decides how this water is rated.
Recent sample results
The last 12 bacterial samples published by the Environmental Protection Agency (Ireland), most recent on the right. Counts are per 100 ml of water.
Dashed line: 500 E. coli per 100 ml, the Bathing Water Directive guide value for coastal / transitional waters.
| Date | E. coli | Enterococci | Assessment |
|---|---|---|---|
| 7 Sept | 62 | 3 | Excellent |
| 10 Aug | 10 | 1 | Excellent |
| 13 Jul | 10 | 4 | Excellent |
| 22 Jun | 20 | 1 | Excellent |
| 2 Jun | 249 | 12 | Excellent |
| 25 May | 10 | 1 | Excellent |
A bathing water's official classification is calculated from percentiles across four bathing seasons, not from any single sample — so one high reading doesn't mean a spot is unsafe, and one low reading doesn't mean it's clean today.
Quality over the last 4 years
- Good2022
- Excellent2023
- Excellent2024
- Excellent2025
This water has improved, from Good in 2022 to Excellent in 2025.
Facilities & access
- Lifeguard
- No
- Parking
- Yes
- Toilets
- No
- Accessible entry
- Yes
- Dogs
- Yes
- Public transport
- No
Official water quality
Classified Excellent in 2025.
Portarthur, Derrybeg is classified as achieving Excellent Water Quality in 2025 based on the assessment of bacteriological results for the period 2022 to 2025. Portarthur, Derrybeg achieved an Excellent Water Quality rating in 2023 and 2024 and a Good Water Quality rating in 2022. Annual water quality ratings are generally calculated using monitoring results over a four-year period and are assessed against stringent bacterial limits to protect bather health.
Official bathing-water profileCommon questions
- Can you swim at Portarthur, Derrybeg right now?
- Portarthur, Derrybeg is currently marked "Good to go". No current pollution alerts — always assess conditions yourself. This reflects the latest data published by the Environmental Protection Agency (Ireland). Conditions change quickly — always assess the water yourself before entering.
- What is the water quality like at Portarthur, Derrybeg?
- the Environmental Protection Agency (Ireland) classified Portarthur, Derrybeg as Excellent in 2025. Classifications are a rolling assessment of bacterial samples taken over four bathing seasons, measured against E. coli and intestinal enterococci limits set by the EU Bathing Water Directive.
- Is there a swimming ban or warning at Portarthur, Derrybeg?
- There are no active bathing restrictions published by the Environmental Protection Agency (Ireland) for Portarthur, Derrybeg. That is not a guarantee of safety — assess conditions yourself.
- Is there a lifeguard at Portarthur, Derrybeg?
- No lifeguard cover is listed for Portarthur, Derrybeg. Never swim alone at an unguarded spot.
- What facilities are there at Portarthur, Derrybeg?
- Portarthur, Derrybeg has parking, accessible entry. Facility information is published by the Environmental Protection Agency (Ireland).
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Nearby swimming spots
See all swimming spots near Falcarragh — about 14 km away.