Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 24 Aug 2026:
- Most powerful swell: Monday 31 Aug, 1PM (local time) - 6.5ft (2.0m), 6s period, NW swell with 297 kJ wave energy.
Best Forecast Surf Conditions for Trearddur Bay (Holy Island) this week:
The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 2.0m 6s and forecast to arrive on Monday (Aug 31) at 1PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 5s period and expected on Saturday (Aug 29) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1PM (Mon 31st Aug) | 6.5ft (2.0m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, I’ll run through it again, this time in feet and miles per hour.
Straight up, the whole 16-day stretch is a tough one for Trearddur Bay. First few days from Monday 24th August to Thursday 27th August are totally flat—basically 0.3 ft or less, with poor conditions. The water temp is 63°, which is a touch warmer than the usual for this time of year. But the swell? Nothing.
There’s a break on Friday 28th August morning when the swell bumps to 3 ft from the SSW, with a short 8 second period and combined energy of 101 (moderate). The wind is cross-onshore from the W at 9 mph, making it fairly choppy. That’s the faintest hope. Saturday 29th is a dud. Sunday 30th gets chunky in the afternoon—6 ft from the SSW, 6 second period, energy 255 (strong), but cross-onshore winds at 22 mph. It’s lumpy and borderline kite-surf territory.
Monday 31st August offers 5 ft from the NW with a 6 second period, energy 250 (strong), and the wind goes cross-shore from the NW at 9 mph in the afternoon. That might be your best shot, but it’s short period and won’t hold shape well.
Rolling into September, the 1st and 2nd are small and messy. Wednesday 3rd September brings 6 ft from the SW with a 6 second period, but the wind is a near gale 34 mph cross-onshore—completely blown out. Not worth it.
Sunday 6th September sees the biggest swell of the period: 15 ft from the SSW, 9 second period, and energy at 3237 (very strong). But the wind is onshore from the SW at 12 mph. That’s huge, messy, and dangerous for a beach break. Only for experts, and even then, it’s ugly.
Monday 7th September holds 8 ft from the WSW, cross-onshore wind at 22 mph, energy 484 (strong). Again, lumpy and poor.
No standouts. The best you might get is Monday 31st August afternoon or Friday 28th August morning, but both are average at best. Otherwise, it’s a long stretch of poor surf. For Trearddur Bay, that’s just how it goes sometimes. Forecasts can change, but right now, I’d say hang it up.
Rusty.
Short Range ForecastLight rain (total 4mm), mostly falling on Tue night. Warm (max 20°C on Tue night, min 13°C on Mon night). Mainly fresh winds. | Days 4-6 Weather SummaryLight rain (total 9mm), mostly falling on Sat afternoon. Very mild (max 17°C on Thu morning, min 14°C on Sat afternoon). Wind will be generally light. | ||||||||||||||||||||
Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | Sunday 30 | |||||||||||||||
AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map |  |  |  |  |  |  |  | ||||||||||||||
Wave Height (m) Direction Period (s) | SW 14 | SW 13 | SW 13 | SW 13 | SW 13 | SSW 8 | SW 8 | SSW 8 | SSW 7 | SSW 7 | SSW 7 | SSW 8 | SSW 8 | SSW 8 | WNW 5 | WSW 4 | SW 6 | SW 6 | SSW 6 | SSW 6 | SW 7 |
Wave Graph  | |||||||||||||||||||||
 kJ | 8 | 7 | 7 | 7 | 7 | 7 | 17 | 12 | 5 | 6 | 5 | 51 | 101 | 88 | 83 | 26 | 5 | 15 | 42 | 255 | 106 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-off | off | cross-off | cross-off | cross-off | off | cross-on | on | cross-on | cross-on | cross-on | cross | on | cross-on | cross-on | cross-on | cross-on | on |
High Tide | 9:19PM4.79m | 9:52AM4.67m | 9:59PM5.08m | 10:26AM4.89m | 10:33PM5.32m | 10:57AM5.08m | 11:04PM5.51m | 11:27AM5.23m | 11:36PM5.65m | 11:57AM5.33m | 00:07AM5.72m | 12:28PM5.40m | 00:40AM5.74m | ||||||||
Low Tide | 3:05PM2.09m | 3:35AM1.78m | 3:46PM1.80m | 4:11AM1.47m | 4:21PM1.52m | 4:43AM1.19m | 4:52PM1.28m | 5:14AM0.96m | 5:23PM1.07m | 5:44AM0.80m | 5:55PM0.94m | 6:16AM0.70m | 6:28PM0.87m | ||||||||
 | |  |  | |  | |  | | |  | |  | | | |  | | |  | | |
 | 6:13 | — | — | 6:13 | — | — | 6:16 | — | — | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — | 6:22 | — | — |
 | — | 8:27 | — | — | 8:24 | — | — | 8:22 | — | — | 8:20 | — | — | 8:17 | — | — | 8:15 | — | — | 8:13 | — |
mm | — | — | — | — | — | 2 | — | 1 | 1 | — | 1 | — | — | — | — | — | 7 | 1 | 1 | 4 | 4 |
Temp °C | 18 | 19 | 19 | 18 | 18 | 20 | 19 | 20 | 19 | 17 | 17 | 17 | 16 | 16 | 16 | 16 | 15 | 15 | 16 | 17 | 16 |
Feels °C | 16 | 16 | 15 | 14 | 15 | 15 | 20 | 20 | 18 | 17 | 17 | 16 | 15 | 14 | 13 | 13 | 14 | 13 | 12 | 11 | 10 |
Swell 1 Height (m) Direction Period (s) | SW 10 | — | SW 13 | SE 4 | SW 13 | SSW 8 | NE 5 | SSW 8 | SSW 7 | NNE 4 | SSW 7 | SSW 8 | — | SSW 8 | SSW 7 | NNW 5 | WNW 4 | — | — | — | SW 7 |
| kJ | 4 | — | 7 | 1 | 7 | 7 | 8 | 12 | 5 | 2 | 5 | 51 | — | 88 | 18 | 24 | 3 | — | — | — | 106 |
Swell 2 Height (m) Direction Period (s) | SW 14 | SW 9 | SW 9 | SW 13 | SW 8 | S 13 | SW 8 | NNE 4 | NNE 4 | SSW 7 | NNE 4 | — | — | SW 8 | S 11 | — | NNW 5 | — | — | — | — |
| kJ | 8 | 3 | 3 | 7 | 3 | 3 | 17 | 4 | 2 | 5 | 1 | — | — | 35 | 2 | — | 5 | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | SW 13 | SW 9 | SW 8 | — | — | SE 4 | — | S 12 | SW 12 | S 3 | — | — | — | — | — | SW 6 | — | — | — | — |
| kJ | — | 7 | 3 | 3 | — | — | 1 | — | 3 | 6 | 1 | — | — | — | — | — | 5 | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | — | E 3 | ENE 5 | NE 5 | NE 4 | — | N 5 | — | SSW 3 | — | — | SSW 8 | NW 4 | WNW 5 | WSW 4 | SW 4 | SW 6 | SSW 6 | SSW 6 | — |
| kJ | — | — | 7 | 9 | 9 | 10 | — | 2 | — | 2 | — | — | 101 | 17 | 83 | 26 | 3 | 15 | 42 | 255 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 246 | 249 | 246 | 249 | 249 | 189 | 315 | 267 | 275 | 249 | 179 | 51 | 51 | 219 | 193 | 186 | 249 | 283 | 286 | 275 | 246 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
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Information about the Trearddur Bay (Holy Island) Surf forecast
The above surf forecast table for Trearddur Bay (Holy Island) provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Trearddur Bay (Holy Island) can be found by selecting the local surf guide option on the grey menu. Our Trearddur Bay (Holy Island) surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Trearddur Bay (Holy Island)) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Trearddur Bay (Holy Island) may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Are you planning a holiday in Anglesy? If you are looking for accommodation near Trearddur Bay (Holy Island), camping, hotels and holiday cottages in Anglesy, consider staying in Holyhead which is 4 km (2 miles) away. Other places in and around Anglesy where you can find information about places to rent, and car hire include Anglesey which is 7 km (4 miles) away, Bangor, Porthmadog and Llandudno.
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