Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 6 Sep 2026:
- Most powerful swell: Saturday 12 Sep, 10PM (local time) - 5.5ft (1.7m), 6s period, SW swell with 245 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 1.7m 6s and forecast to arrive on Saturday (Sep 12) at 10PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.5m 6s period and expected on Wednesday (Sep 09) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Sat 12th Sep) | 5.5ft (1.7m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, let’s get real about this stretch. I’m looking at Trearddur Bay on Holy Island, and honestly, it’s a tough watch for the next couple of weeks. This setup is about as beginner-friendly as it gets when it’s on, but the problem is it’s barely ever on. The swell direction from the SW is what the spot wants, but we’re getting a lot of wind from the wrong angles—mostly cross-onshore and onshore—which is just trashing what little wave energy we have.
The forecast kicks off on Sunday, September 6th, with a bit of swell around 5ft from the SSW, but the wind is a fresh 22 mph cross-on shore, and the period is a short, weak 6 seconds. The combined energy is only 122, which is weak, and the onshore wind is just making it lumpy. There’s really nothing to get excited about here. This pattern of messy, wind-affected surf continues day after day, with a gap of several days where conditions are just poor. The swell bumps up a bit on the 15th, with 6ft from the SW and a bit more energy (209 in the morning), but the wind is still cross-on or onshore, keeping it choppy. For a spot that’s inconsistent like Trearddur Bay, this is a real bummer.
The only hint of something a little cleaner comes late on Friday, September 11th, when the wind swings to a light 12 mph cross-off from the NNW, offering a clean window. But the swell is tiny at 2ft from the SW, so you’re looking at knee-high dribble. There’s another moment on Friday, September 18th, with a light breeze and a cross-shore wind, and 5ft of SW swell, but the period is still short at 6 seconds, and the energy is moderate at 128. It’s the best of a bad bunch, but it’s not a standout.
Look, for a beginner spot that’s already inconsistent, this run of poor surf is tough. The water temperature is about average for the time of year, so at least you won’t freeze while you’re sitting there waiting for a set. But honestly, for the whole 16 days, there’s not a single standout day. If you’re in the area, don’t bother paddling out. The wind and swell just aren’t lining up. Stay home and wax your board for a better day.
Rusty.
Short Range ForecastLight rain (total 5mm), mostly falling on Mon night. Very mild (max 19°C on Sun afternoon, min 13°C on Mon night). Mainly strong winds. | Days 4-6 Weather SummaryLight rain (total 2mm), mostly falling on Thu night. Very mild (max 17°C on Thu night, min 13°C on Tue night). Winds decreasing (strong winds from the WNW on Tue night, light winds from the N by Fri afternoon). | ||||||||||||||||||||
Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | |||||||||||||||
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) | SSW 6 | SSW 6 | SW 6 | SW 14 | SW 5 | SW 6 | W 5 | W 5 | WNW 6 | SW 6 | WSW 4 | SW 3 | SW 5 | SSW 6 | SW 7 | SSW 7 | SW 6 | SW 6 | SW 7 | SSW 6 | SW 7 |
Wave Graph  | |||||||||||||||||||||
 kJ | 115 | 197 | 142 | 33 | 67 | 136 | 90 | 106 | 207 | 11 | 15 | 5 | 59 | 107 | 91 | 29 | 21 | 10 | 11 | 173 | 195 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | on | cross-on | cross-on | cross-on | cross-on | cross-on | cross | cross | cross-on | cross-on | cross-on | cross-on | on | cross | cross-off | cross | cross-on | cross-on | on |
High Tide | 6:18AM4.51m | 7:01PM4.59m | 7:54AM4.65m | 8:23PM4.91m | 9:02AM4.96m | 9:21PM5.29m | 9:53AM5.26m | 10:08PM5.63m | 10:36AM5.47m | 10:49PM5.85m | 11:14AM5.59m | 11:28PM5.95m | 11:50AM5.61m | 00:04AM5.91m | |||||||
Low Tide | 12:31PM2.14m | 1:25AM1.84m | 1:57PM1.96m | 2:38AM1.44m | 3:00PM1.61m | 3:33AM1.02m | 3:50PM1.24m | 4:19AM0.68m | 4:32PM0.95m | 5:00AM0.47m | 5:11PM0.75m | 5:39AM0.42m | 5:49PM0.68m | ||||||||
 |  |  | |  |  |  | | | | |  | | |  | | | | |  | | |
 | 6:35 | — | — | 6:37 | — | — | 6:39 | — | — | 6:39 | — | — | 6:41 | — | — | 6:43 | — | — | 6:45 | — | — |
 | — | 7:57 | — | — | 7:53 | — | — | 7:52 | — | — | 7:50 | — | — | 7:46 | — | — | 7:45 | — | — | 7:42 | — |
mm | 1 | — | — | — | — | 3 | — | — | — | — | — | — | — | — | 2 | — | — | — | — | 3 | — |
Temp °C | 17 | 19 | 17 | 15 | 16 | 16 | 14 | 15 | 14 | 14 | 16 | 15 | 15 | 16 | 17 | 15 | 15 | 14 | 16 | 16 | 17 |
Feels °C | 10 | 12 | 13 | 11 | 9 | 9 | 6 | 8 | 6 | 8 | 12 | 11 | 11 | 12 | 15 | 11 | 12 | 12 | 9 | 10 | 13 |
Swell 1 Height (m) Direction Period (s) | SW 13 | SW 13 | — | SW 14 | NW 4 | SW 12 | SW 11 | SW 11 | S 11 | SW 6 | NNW 5 | NNW 4 | — | — | SW 7 | SSW 7 | SW 6 | SW 6 | SW 7 | — | — |
| kJ | 7 | 6 | — | 33 | 1 | 6 | 5 | 4 | 2 | 11 | 30 | 3 | — | — | 91 | 29 | 21 | 10 | 11 | — | — |
Swell 2 Height (m) Direction Period (s) | — | — | SW 17 | — | — | — | — | — | — | SW 10 | — | NW 4 | — | — | — | — | — | NNW 5 | — | — | — |
| kJ | — | — | 11 | — | — | — | — | — | — | 4 | — | 1 | — | — | — | — | — | 4 | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | SSW 6 | SSW 6 | SW 6 | WSW 4 | SW 5 | SW 6 | W 5 | W 5 | WNW 6 | NW 6 | WSW 4 | SW 3 | SW 5 | SSW 6 | — | NW 4 | NW 4 | — | SSE 3 | SSW 6 | SW 7 |
| kJ | 115 | 197 | 142 | 23 | 67 | 136 | 90 | 106 | 207 | 141 | 15 | 5 | 59 | 107 | — | 29 | 18 | — | 5 | 173 | 195 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 312 | 446 | 210 | 51 | 246 | 219 | 280 | 378 | 346 | 346 | 273 | 246 | 275 | 246 | 280 | 179 | 307 | 161 | 238 | 250 | 251 |
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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