Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 7 Aug 2026:
- Most powerful swell: Thursday 13 Aug, 4PM (local time) - 1.5ft (0.4m), 8s period, SW swell with 22 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 0.4m 8s and forecast to arrive on Thursday (Aug 13) at 4PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 2s period and expected on Monday (Aug 10) at 10PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4PM (Thu 13th Aug) | 1.5ft (0.4m) 8s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, let’s be real with you. The next couple of weeks are looking pretty flat and sad for Trearddur Bay. I’ve been staring at the charts and there’s just nothing doing for a good long while. We’re talking a solid stretch of marginal, knee-high dribble and onshore slop that’s going to have you wondering why you bothered dragging your board down.
The first real tease of a wave doesn’t show up until Sunday the 16th, and even then it’s a grovelly 0.9m (3ft) with a short, weak 4-second period. The energy is still weak, only 33 in the combined swell energy for the morning. It’s a gentle cross-onshore, so it’ll be a bit lumpy. Not worth getting excited about. The following morning, Monday the 17th, sees a bit more size, 1.3m (4ft), but the period is a pathetic 5 seconds, and it’s a cross-onshore breeze again. Still poor, still not really breaking properly.
Then, finally, we get something that looks like a pulse. On Tuesday the 18th, the swell builds to 1.8m (6ft) with a 6-second period, and the combined energy jumps to a moderate 193. This is the most significant swell of the entire window, coming from the SSW. But, as is the way here, the wind decides to be a pain. It’s a light cross-onshore in the morning, turning more onshore in the afternoon. For a beginner break, 1.8m (6ft) is already in the “might be a bit much” territory, but the short period is the real killer. It’s going to be a jumbled, messy closeout, not a clean, rideable wave. This is the closest thing to a standout, but honestly, it’s not a glowing recommendation. If you’re an experienced local who knows the sandbars, Tuesday morning is your only real window to get something with a bit of push behind it, but it’s not going to be pretty.
After that, it just kind of gives up again. The rest of the week is a mix of small, weak swells and poor winds. The 21st brings strong onshores and a tiny 0.6m (2ft) wave, which will be pure chop. The water temp is about average for the time of year, so you won't need the 5mm just yet.
So, there you have it. A long, drawn-out flat spell with one possible, average-quality bump on Tuesday the 18th. It’s not ideal, but it is what it is. Keep the board in the car just in case, because forecasts can change, but plan for a lot of time on the beach.
Rusty
Short Range ForecastMostly dry. Very mild (max 19°C on Sun afternoon, min 14°C on Fri night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 24°C on Tue afternoon, min 14°C on Mon morning). Wind will be generally light. | ||||||||||||||||||||
Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | |||||||||||||||
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 4 | SW 5 | SSW 4 | SSW 4 | SSW 4 | SW 4 | SW 4 | SW 4 | SW 6 | SSW 6 | SSW 6 | SW 6 | SW 6 | S 4 | SSW 4 | SW 12 | S 12 | SW 4 | WNW 4 | SW 8 | SW 7 |
Wave Graph  | |||||||||||||||||||||
 kJ | 6 | 6 | 12 | 16 | 13 | 14 | 7 | 6 | 1 | 4 | 3 | 1 | 2 | 2 | 4 | 5 | 4 | 18 | 11 | 22 | 7 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | cross-on | cross-on | cross-on | cross-on | on | on | cross | cross-off | cross-off | off | cross-on | on | cross | cross-on | on | cross-on | cross-on | on | cross |
High Tide | 5:37PM4.56m | 6:16AM4.64m | 7:05PM4.57m | 7:47AM4.68m | 8:27PM4.80m | 9:03AM4.91m | 9:30PM5.16m | 10:01AM5.19m | 10:21PM5.51m | 10:50AM5.42m | 11:07PM5.78m | 11:35AM5.56m | 11:49PM5.94m | ||||||||
Low Tide | 11:18AM1.72m | 11:58PM1.91m | 12:38PM1.85m | 1:25AM1.83m | 1:59PM1.77m | 2:41AM1.51m | 3:06PM1.52m | 3:41AM1.10m | 4:01PM1.21m | 4:33AM0.72m | 4:48PM0.94m | 5:19AM0.45m | 5:32PM0.74m | ||||||||
 | |  |  | | |  | | | | |  | | | | | | | | | | |
 | 5:43 | — | — | 5:45 | — | — | 5:47 | — | — | 5:48 | — | — | 5:50 | — | — | 5:52 | — | — | 5:54 | — | — |
 | — | — | 9:02 | — | — | 9:00 | — | 8:59 | — | — | 8:57 | — | — | 8:54 | — | — | 8:52 | — | — | 8:51 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 15 | 16 | 15 | 16 | 17 | 16 | 17 | 19 | 18 | 15 | 17 | 19 | 22 | 24 | 24 | 23 | 20 | 18 | 16 | 19 | 18 |
Feels °C | 13 | 12 | 11 | 12 | 13 | 12 | 16 | 17 | 18 | 12 | 13 | 17 | 19 | 23 | 22 | 18 | 16 | 16 | 14 | 16 | 15 |
Swell 1 Height (m) Direction Period (s) | SW 4 | WNW 3 | SW 12 | SW 11 | S 11 | SW 7 | SW 6 | SSW 6 | — | NNW 3 | SSW 6 | SW 6 | SW 6 | S 4 | — | SW 12 | SW 10 | SW 9 | SW 4 | NW 4 | SW 3 |
| kJ | 4 | 1 | 5 | 5 | 2 | 2 | 2 | 3 | — | 1 | 3 | 1 | 2 | 2 | — | 5 | 4 | 3 | 2 | 2 | 2 |
Swell 2 Height (m) Direction Period (s) | SW 12 | S 12 | — | — | — | S 11 | S 12 | SW 12 | SW 6 | SSW 6 | — | — | — | SW 6 | SW 6 | S 6 | — | WSW 9 | SW 8 | NW 4 | SW 7 |
| kJ | 6 | 3 | — | — | — | 2 | 3 | 6 | 1 | 4 | — | — | — | 2 | 1 | 1 | — | 8 | 3 | 2 | 7 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | SW 12 | — | — | — | — | — | — | S 11 | — | S 12 | — | SW 4 | — | S 11 |
| kJ | — | — | — | — | — | — | — | 6 | — | — | — | — | — | — | 2 | — | 3 | — | 2 | — | 2 |
Wind waves Height (m) Direction Period (s) | NW 3 | SW 5 | SSW 4 | SSW 4 | SSW 4 | SW 4 | SW 4 | SW 4 | — | — | — | ENE 2 | SSE 3 | — | SSW 4 | S 3 | SSW 3 | SW 4 | WNW 4 | SW 8 | — |
| kJ | 2 | 6 | 12 | 16 | 13 | 14 | 7 | 3 | — | — | — | 1 | 1 | — | 4 | 4 | 2 | 18 | 11 | 22 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 280 | 251 | 246 | 246 | 246 | 246 | 368 | 388 | 246 | 246 | 255 | 249 | 286 | 306 | 267 | 206 | 287 | 192 | 192 | 358 | 179 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
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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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