- Water quality Excellent sampled 2 Sep 2026
- Sea temp 14.8 °C surface, modelled
- Air 13 °C Partly cloudy
- Wind 16 mph from NW · gust 26
- Next tide Low 03:08 tomorrow · 0.6 m
Portmuck is a coastal beach on the Antrim Coast coast, in the Mid and East Antrim Borough Council.
Conditions now
Air
13°C
Partly cloudy
Sea temp
14.8°C
surface, modelled
Wind
16mph
from NW · gust 26 mph
Sea state1.4 mperiod 5 s · NW
Swell0.4 m8 s · NW
Rain, 48 h2 mm
Water quality
Latest sample 2 Sep 2026: Excellent — E. coli 10, intestinal enterococci 10 CFU/100 ml
Sample history (40 shown)
| Date | E. coli | Ent. | Rating | Algae |
|---|---|---|---|---|
| 2 Sep 2026 | 10 | 10 | Excellent | — |
| 26 Aug 2026 | 29 | 10 | Excellent | — |
| 21 Aug 2026 | 10 | 10 | Excellent | — |
| 13 Aug 2026 | 10 | 10 | Excellent | — |
| 10 Aug 2026 | 10 | 10 | Excellent | — |
| 5 Aug 2026 | 10 | 10 | Excellent | — |
| 28 Jul 2026 | 12 | 10 | Excellent | — |
| 24 Jul 2026 | 10 | 10 | Excellent | — |
| 20 Jul 2026 | 10 | 10 | Excellent | — |
| 17 Jul 2026 | 15 | 10 | Excellent | — |
| 8 Jul 2026 | 10 | 10 | Excellent | — |
| 2 Jul 2026 | 70 | 29 | Excellent | — |
| 22 Jun 2026 | 26 | 49 | Excellent | — |
| 16 Jun 2026 | 10 | 10 | Excellent | — |
| 9 Jun 2026 | 21 | 10 | Excellent | — |
| 4 Jun 2026 | 470 | 70 | Good | — |
| 1 Jun 2026 | 55 | 40 | Excellent | — |
| 26 May 2026 | 200 | 40 | Excellent | — |
| 8 Sep 2025 | 10 | 10 | Excellent | — |
| 2 Sep 2025 | 10 | 10 | Excellent | — |
| 28 Aug 2025 | 41 | 50 | Excellent | — |
| 20 Aug 2025 | 10 | 10 | Excellent | — |
| 15 Aug 2025 | 10 | 10 | Excellent | — |
| 11 Aug 2025 | 10 | 10 | Excellent | — |
| 8 Aug 2025 | 10 | 19 | Excellent | — |
| 30 Jul 2025 | 10 | 10 | Excellent | — |
| 29 Jul 2025 | 1600 | 200 | NoBathing | — |
| 24 Jul 2025 | 26 | 10 | Excellent | — |
| 16 Jul 2025 | 110 | 10 | Excellent | — |
| 8 Jul 2025 | 10 | 10 | Excellent | — |
| 3 Jul 2025 | 10 | 10 | Excellent | — |
| 30 Jun 2025 | 10 | 10 | Excellent | — |
| 24 Jun 2025 | 190 | 100 | Excellent | — |
| 20 Jun 2025 | 10 | 10 | Excellent | — |
| 18 Jun 2025 | 10 | 10 | Excellent | — |
| 12 Jun 2025 | 10 | 10 | Excellent | — |
| 6 Jun 2025 | 10 | 10 | Excellent | — |
| 2 Jun 2025 | 10 | 10 | Excellent | — |
| 28 May 2025 | 10 | 10 | Excellent | — |
| 20 May 2025 | 15 | 10 | Excellent | — |
Weekly lab samples, not real-time. Avoid bathing for 48 h after heavy rain. Bathing Water Profile (PDF).
Sewage & storm overflows
2 NI Water storm overflows within 1.2 mi.
Nearest 2
| Overflow | Distance | Classification | Spills/yr | Monitored |
|---|---|---|---|---|
| Mullaghboy Islandmagee FA CSO | 0.7 mi | To be Determined | — | — |
| Ros Na Righ WwPS → Larne Lough |
1.1 mi | To be Determined | — | — |
Nearest wastewater treatment works: Mullaghboy Islandmagee WwTW (0.7 mi → North Channel) · Ferris Bay 50 ST (2.0 mi → Larne Lough).
Spill figures are modelled annual predictions, not measured events. Classification is NI Water's own.
Amenities nearby & features
Parking
2
Toilets
1
Picnic tables
7
Boating — nearest harbours & marinas
- Islandmagee 70 yd
- Ballylumford 2.5 mi
- Larne 2.8 mi
- Whitehead 6.4 mi
- Unknown 7.3 mi
Kind and ownership are DAERA's own classification. The feed carries no per-site facility data — call ahead for berthing, fuel, water or shore power.
Wildlife & designations
This beach lies in or within 0.6 mi of:
- ASSI Portmuck
- ASSI The Gobbins
- SAC North Channel
Alerts & advisories
Weever fish
Lesser weever fish bury themselves in wet sand around the low-tide line in summer and have venomous dorsal spines. Wear beach shoes and shuffle your feet in the shallows. A sting is intensely painful but rarely serious: immerse the foot in water as hot as you can tolerate (about 40 C) for 30-90 minutes and seek help if a spine remains or swelling spreads.
Rip currents on surf beaches
The open Atlantic strands generate strong rip currents, particularly around low tide and after big swell. Swim between the red-and-yellow flags at lifeguarded beaches in season, never alone, and if caught in a rip do not swim against it: raise a hand, float, and let it carry you out until it releases.
Midges and clegs
Biting midges and clegs (horseflies) are worst on warm, still, overcast days and around dawn and dusk from late spring to early autumn, especially near dunes, marram grass and standing water. A breeze off the sea keeps them down. Cover up or use repellent at the back of the beach.
Jellyfish
Lion's mane and compass jellyfish are common off the Northern Ireland coast in summer and are often blown inshore and stranded after onshore winds. Lion's mane stings can be severe. Do not rub a sting; rinse with seawater, remove tentacles with a gloved hand or card, and use hot water or a cold pack for pain.
Seasonal dog restrictions
Many Northern Ireland councils restrict dogs from the main bathing area, or require dogs on leads, between 1 May and 30 September (Blue Flag beaches usually exclude dogs from the bathing zone entirely in season). Rules and dates vary by beach and council: check the signage at the entrance and your council's bathing-beach byelaws.