Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 17 Jul 2026:
- Most powerful swell: Friday 17 Jul, 1PM (local time) - 0.5ft (0.1m), 12s period, SW swell with 6 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 0.1m 12s and forecast to arrive on Friday (Jul 17) at 1PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.4m 6s period and expected on Wednesday (Jul 22) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1PM (Fri 17th Jul) | 0.5ft (0.1m) 12s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright crew, Rusty here. Let's chew the fat on what Trearddur Bay is cookin' up.
Gotta be honest, this is a grim one. We're looking at a proper dry spell. From the 17th of July all the way through to the morning of the 24th, it's just flat and hopeless. The wind's been blowing cross-off, which is clean, but with no swell to push, it's a total glass-off. Nothing to ride.
The first hint of anything comes on the morning of Thursday, the 24th of July. The combined energy (33) is still weak, but we get a little 3ft swell from the WNW with a 5-second period. It's a short-period windswell, and with a 25 km/h cross-onshore wind, it's going to be a choppy, bumpy mess. The afternoon is even worse with onshore wind. This is more of a kite day than a surf day, if you ask me.
The best of a bad bunch might be the morning of Saturday, the 26th of July. We've got a similar 3ft swell from the NW, still short period at 4 seconds, and the energy is low (27). The wind is a gentle cross-shore, so it'll be a little cleaner, but the waves will be weak and crumbly. It's not good, it's just the least bad option.
After that, it all dries up again. By the 29th of July, it's flat. There's a moment on the afternoon of the 30th of July with glassy conditions, but no swell to go with it. So, for the next 16 days, Trearddur Bay is a no-go. The charts can always flip, but right now, leave the board at home.
Rusty.
Short Range ForecastMostly dry. Very mild (max 18°C on Fri morning, min 12°C on Fri night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Very mild (max 18°C on Tue afternoon, min 13°C on Mon morning). Mainly fresh winds. | ||||||||||||||||||||
Friday 17 | Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | Thursday 23 | |||||||||||||||
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 12 | SW 11 | S 11 | S 11 | S 11 | S 10 | S 10 | N 5 | NNW 5 | NNW 5 | NNW 5 | N 4 | N 6 | NNW 6 | N 6 | N 6 | NNW 6 | NNW 5 | N 4 |
Wave Graph  | |||||||||||||||||||||
 kJ | 4 | 6 | 6 | 5 | 2 | 2 | 2 | 2 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-off | cross-off | off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off |
High Tide | 1:23PM5.44m | 1:37AM5.79m | 2:08PM5.28m | 2:22AM5.60m | 2:52PM5.06m | 3:07AM5.33m | 3:38PM4.82m | 3:53AM5.01m | 4:26PM4.58m | 4:45AM4.69m | 5:23PM4.40m | 5:49AM4.42m | 6:33PM4.31m | ||||||||
Low Tide | 7:20PM0.84m | 7:55AM0.51m | 8:05PM1.00m | 8:41AM0.77m | 8:50PM1.23m | 9:27AM1.09m | 9:37PM1.52m | 10:16AM1.45m | 10:29PM1.82m | 11:11AM1.78m | 11:31PM2.09m | 12:17PM2.03m | 00:48AM2.22m | ||||||||
 |  |  | | |  | | | | | | | | | | | | | | | | |
 | 5:11 | — | — | 5:11 | — | — | 5:13 | — | — | 5:15 | — | — | 5:16 | — | — | 5:18 | — | — | 5:20 | — | — |
 | — | — | 9:36 | — | — | 9:35 | — | — | 9:34 | — | — | 9:32 | — | — | 9:30 | — | — | 9:30 | — | — | 9:28 |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 18 | 18 | 18 | 14 | 16 | 18 | 15 | 17 | 16 | 14 | 17 | 16 | 17 | 18 | 17 | 15 | 17 | 16 | 16 | 18 | 18 |
Feels °C | 13 | 13 | 15 | 9 | 12 | 16 | 12 | 13 | 13 | 10 | 14 | 13 | 13 | 15 | 15 | 12 | 13 | 12 | 13 | 15 | 15 |
Swell 1 Height (m) Direction Period (s) | SSW 6 | SSW 6 | SW 6 | SW 6 | SW 6 | N 5 | NNW 4 | S 10 | S 10 | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 4 | 4 | 1 | 1 | 1 | 19 | 3 | 2 | 2 | — | — | — | — | — | — | — | — | — | — | — | — |
Swell 2 Height (m) Direction Period (s) | S 12 | SW 12 | SW 12 | SW 11 | S 11 | S 11 | S 11 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 3 | 6 | 6 | 5 | 2 | 2 | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | S 5 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | NNW 3 | N 3 | N 4 | NNW 6 | NNW 6 | — | — | N 4 | N 4 | N 5 | NNW 5 | NNW 5 | NNW 5 | N 4 | N 6 | NNW 6 | N 6 | N 6 | NNW 6 | NNW 5 | N 4 |
| kJ | 4 | 6 | 10 | 92 | 134 | — | — | 2 | 12 | 24 | 17 | 35 | 24 | 12 | 106 | 150 | 94 | 83 | 50 | 19 | 6 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 326 | 326 | 589 | 317 | 284 | 284 | 277 | 284 | 292 | 273 | 284 | 318 | 273 | 306 | 1003 | 59 | 887 | 927 | 59 | 273 | 283 |
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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