Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 9 Aug 2026:
- Most powerful swell: Sunday 9 Aug, 4PM (local time) - 1.5ft (0.4m), 6s period, SW swell with 9 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 6s and forecast to arrive on Sunday (Aug 09) 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 1.1m 6s period and expected on Saturday (Aug 15) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4PM (Sun 9th Aug) | 1.5ft (0.4m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s be straight with you—it’s a tough watch out there for the next couple of weeks. We’ve got a long stretch of flat, weak, and messy conditions ahead, so if you’re Jonesing for a wave, you’re going to need some patience.
The whole 16-day window is looking pretty bleak, with no good surf on offer. We’re talking about a solid run of days with hardly any swell and a lot of onshore junk. The first week is particularly dead, with wave heights barely reaching 2 to 2 feet, and periods that are all over the place. The energy just isn’t there, with combined energy values mostly in the single digits. The winds aren't helping either, with a lot of cross-on and onshore breezes chopping up what little texture there is.
The only real standout in this whole stretch – and I mean the only one – is around the 20th of August. We finally get some proper swell energy, but it’s still not great. Here’s the call: on Thursday morning, the 20th, we see a modest push of about 4 feet from the WNW. The combined energy jumps to a moderate level, and it’s the best we’re going to see. But the wind is straight cross-shore, blowing at 12 mph from the WNW, so it’ll be a bit of a bumpy, cross-chop mess.
That’s not the wave to get excited about. The real, albeit small, highlight comes on Saturday the 22nd. We get a moderate offshore breeze from the ENE at 12 mph, and while the swell is tiny – just 0.5 feet from the SW – it’s clean. With a long period of 13-16 seconds, it’ll be glassy and lined up, but it’s for a longboard only.
Trearddur Bay (Holy Island) is the spot, but it's inconsistent and won't be breaking much. The water is running at 62°F, which is a touch warmer than usual for this time of year, so you won't need a thick suit. The long-period swell on the 22nd is the classic setup for a place like this – it can break too straight at the beach, but this spot can handle it a bit better on the right tide.
Honestly, for a beginner, any of these days are a wash. The only real exception is if the wind swings offshore, and you’re just paddling around. But for a proper surf, there’s nothing on offer. The setup looks much more interesting for a kiteboarder than a paddle surfer on those 20th and 23rd. It’s a blank run, plain and simple. Forecasts change, but right now, it’s a waiting game.
Rusty.
Short Range ForecastMostly dry. Warm (max 20°C on Tue morning, min 14°C on Sun night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 24°C on Wed afternoon, min 17°C on Thu night). Wind will be generally light. | |||||||||||||||||||
Sat 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | Friday 14 | ||||||||||||||
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 4 | SW 4 | S 12 | SW 6 | SW 4 | SW 5 | SW 6 | SSW 6 | SW 6 | SSW 3 | SSW 4 | SSW 3 | SSW 4 | SW 9 | SW 8 | SW 11 | S 11 | SSW 4 | SW 4 | SW 4 |
Wave Graph  | ||||||||||||||||||||
 kJ | 9 | 5 | 3 | 9 | 6 | 4 | 5 | 4 | 1 | 3 | 3 | 5 | 5 | 3 | 3 | 4 | 2 | 7 | 5 | 9 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | on | on | cross-off | cross-off | cross-off | cross-off | cross-on | on | cross | cross-on | on | cross-on | glassy | cross | cross-on | on | cross-on | cross-off |
High Tide | 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 | 12:16PM5.58m | 00:30AM5.96m | |||||||
Low Tide | 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 | 6:02AM0.32m | 6:14PM0.67m | ||||||||
 |  | | | |  | | | | | | | |  | | | | | | | |
 | — | — | 5:47 | — | — | 5:48 | — | — | 5:50 | — | — | 5:52 | — | — | 5:54 | — | — | 5:54 | — | — |
 | — | 9:00 | — | 8:59 | — | — | 8:57 | — | — | 8:54 | — | — | 8:52 | — | — | 8:51 | — | — | 8:49 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 17 | 16 | 16 | 17 | 16 | 14 | 16 | 17 | 20 | 21 | 21 | 21 | 24 | 23 | 23 | 23 | 22 | 18 | 20 | 19 |
Feels °C | 13 | 13 | 15 | 15 | 14 | 11 | 13 | 14 | 16 | 18 | 20 | 17 | 21 | 20 | 22 | 21 | 21 | 19 | 21 | 20 |
Swell 1 Height (m) Direction Period (s) | S 11 | SW 7 | SW 6 | — | SW 4 | SW 5 | SW 6 | SSW 6 | SW 6 | — | SSW 4 | SW 12 | SW 10 | SW 9 | — | SW 8 | SW 6 | — | — | SW 4 |
| kJ | 2 | 2 | 2 | — | 4 | 4 | 5 | 4 | 1 | — | 3 | 5 | 4 | 3 | — | 3 | 2 | — | — | 9 |
Swell 2 Height (m) Direction Period (s) | — | S 11 | S 12 | SW 12 | SW 6 | WNW 3 | W 3 | — | — | — | S 6 | W 10 | S 12 | SW 5 | SW 8 | — | SW 8 | — | — | — |
| kJ | — | 2 | 3 | 6 | 1 | 1 | 1 | — | — | — | 1 | 2 | 3 | 1 | 3 | — | 2 | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | SW 12 | S 8 | — | — | — | — | S 11 | S 6 | — | — | SW 5 | SW 11 | S 11 | — | — | — |
| kJ | — | — | — | — | 6 | 1 | — | — | — | — | 2 | 1 | — | — | 1 | 4 | 2 | — | — | — |
Wind waves Height (m) Direction Period (s) | SSW 4 | SW 4 | SW 3 | SW 6 | NNW 3 | N 4 | N 4 | — | — | SSW 3 | — | SSW 3 | SSW 4 | — | — | — | — | SSW 4 | SW 4 | — |
| kJ | 9 | 5 | 2 | 9 | 3 | 5 | 3 | — | — | 3 | — | 5 | 5 | — | — | — | — | 7 | 5 | — |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 251 | 246 | 292 | 251 | 251 | 251 | 285 | 246 | 286 | 288 | 163 | 155 | 179 | 163 | 178 | 288 | 192 | 192 | 514 | 163 |
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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