Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 20 Aug 2026:
- Best quality surf: Wednesday 26 Aug, 10PM (local time) - 2.5ft (0.8m), 7s period, SSW swell with cross-offshore winds.
- Most powerful swell: Wednesday 26 Aug, 10PM (local time) - 2.5ft (0.8m), 7s period, SSW swell with 64 kJ wave energy.
- Next surfable swell (1★+): Wednesday 26 Aug, 10PM (local time) - 2.5ft (0.8m), 7s period with SSW swell.
Best Forecast Surf Conditions for Trearddur Bay (Holy Island) this week:
The surf forecast for Trearddur Bay (Holy Island) over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Wednesday (Aug 26) at 10PM. The primary swell is predicted to be 0.8m and 7s period with a secondary swell of 0.1m and 12s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 0.8m 7s and forecast to arrive on Wednesday (Aug 26) at 10PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 5s period and expected on Thursday (Aug 20) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 10PM (Wed 26th Aug) | 2.5ft (0.8m) 7s |
| Best Surf | 10PM (Wed 26th Aug) | 2.5ft (0.8m) 7s |
| Most Powerful | 10PM (Wed 26th Aug) | 2.5ft (0.8m) 7s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, surfers, let’s get into it. Rusty here, and I’ve got the goods on what’s coming up for Trearddur Bay (Holy Island). I’ll be straight with you: this isn’t a week for high hopes. We’ve got a long stretch of flat, weak surf ahead, with barely a pulse until the very end of the month.
The first solid recommendation doesn’t show up until Sunday, the 30th of August, and even then, it’s marginal. For the next ten days, from Thursday the 20th through to Saturday the 29th, we’re looking at tiny, wind-affected dribble. Swell heights are mostly below 2 ft, with periods all over the place but the energy is pitiful – often between 7 and 24 (combined energy). The wind is mostly cross-off or cross, which keeps the surface clean, but with practically no wave to ride, it’s just a glassy pond. The water temp is about average for this time of year, so no surprises there.
The standout – if you can call it that – is Sunday the 30th of August. The swell starts to build in the morning, with 5 ft from the SW, period of 6 seconds, and energy hitting 195 (moderate). The wind is cross-on and windy, so it’ll be choppy. By the afternoon, the swell picks up to 8 ft, still from the SW, period 7 seconds, and energy jumps to 495 (strong). That’s a lot of water moving, but the period is short, meaning it’ll be a bit of a mess. Still, the wind goes light cross-shore, so it might be the most rideable slot of the whole run. It’s marginal, but for the desperate, this is it.
Then Monday the 31st of August brings 8 ft from the WSW, period 7 seconds, energy over 500 (strong) – but it’s cross-on and choppy, so only for the hardcore. After that, we get a little relief on Tuesday the 1st of September with 5 ft from the NW, period 5 seconds, and clean cross-off wind. The energy is 152 (moderate). It’s nothing special, but at least the surface is smooth.
The rest of the outlook drops off rapidly after that, with tiny swells and strong winds. So, to sum it up: if you’ve got to paddle, wait for the 30th of August afternoon, and keep your expectations low. It’s not a classic, but it’s the only real chance.
Rusty.
Short Range ForecastLight rain (total 5mm), mostly falling on Thu morning. Very mild (max 16°C on Fri afternoon, min 13°C on Thu night). Winds decreasing (fresh winds from the N on Thu morning, light winds from the N by Sat night). | Days 4-6 Weather SummaryMostly dry. Warm (max 22°C on Mon afternoon, min 14°C on Sun morning). Mainly fresh winds. | ||||||||||||||||||||
Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | |||||||||||||||
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 6 | SW 6 | SW 14 | SW 14 | SW 13 | SW 13 | SW 15 | SW 15 | SW 15 | SW 14 | SW 14 | SW 14 | SW 14 | SW 13 | SW 13 | SW 13 | SW 13 | SW 13 | S 4 | SSW 6 | SSW 7 |
Wave Graph  | |||||||||||||||||||||
 kJ | 16 | 10 | 8 | 7 | 7 | 7 | 8 | 8 | 8 | 8 | 7 | 8 | 8 | 7 | 7 | 7 | 7 | 7 | 15 | 58 | 56 |
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 | cross-off | cross-off | cross-off | off | cross-off | cross-off | cross-off | cross-off | off | cross-off | cross-off | cross-on | cross-off |
High Tide | 4:23PM4.44m | 4:52AM4.29m | 5:32PM4.26m | 6:23AM4.10m | 7:07PM4.27m | 8:04AM4.17m | 8:27PM4.49m | 9:08AM4.41m | 9:19PM4.79m | 9:52AM4.67m | 9:59PM5.08m | 10:26AM4.89m | 10:33PM5.32m | ||||||||
Low Tide | 10:14AM1.98m | 10:37PM2.18m | 11:17AM2.31m | 11:58PM2.41m | 12:45PM2.45m | 1:37AM2.37m | 2:08PM2.34m | 2:47AM2.11m | 3:05PM2.09m | 3:35AM1.78m | 3:46PM1.80m | 4:11AM1.47m | 4:21PM1.52m | ||||||||
 |  |  |  |  | | | | | | | | | |  | | |  | |  |  | |
 | 6:05 | — | — | 6:07 | — | — | 6:09 | — | — | 6:11 | — | — | 6:13 | — | — | 6:13 | — | — | 6:16 | — | — |
 | — | 8:36 | — | — | 8:34 | — | — | 8:31 | — | — | 8:29 | — | — | 8:27 | — | — | 8:24 | — | — | 8:22 | — |
mm | 3 | — | — | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 5 | — | 12 |
Temp °C | 15 | 15 | 15 | 15 | 16 | 14 | 13 | 15 | 15 | 15 | 16 | 16 | 20 | 22 | 20 | 21 | 22 | 21 | 18 | 19 | 17 |
Feels °C | 10 | 9 | 10 | 12 | 11 | 10 | 10 | 13 | 13 | 13 | 14 | 13 | 19 | 18 | 13 | 17 | 19 | 17 | 15 | 17 | 17 |
Swell 1 Height (m) Direction Period (s) | SW 6 | SW 6 | SSW 6 | NNW 5 | W 4 | SW 13 | SW 15 | NNW 5 | NNW 5 | N 4 | N 4 | SW 14 | SW 14 | SW 13 | SW 13 | SSE 4 | NE 5 | NE 4 | SSW 8 | SSW 8 | SSW 7 |
| kJ | 16 | 10 | 3 | 28 | 1 | 7 | 8 | 20 | 7 | 3 | 1 | 8 | 8 | 7 | 7 | 2 | 7 | 1 | 6 | 6 | 56 |
Swell 2 Height (m) Direction Period (s) | SW 15 | SW 14 | SW 14 | SW 6 | SW 6 | — | — | SW 15 | SW 15 | SW 14 | SW 14 | — | SW 9 | — | SW 8 | SW 13 | SW 13 | SW 8 | NE 4 | S 12 | S 12 |
| kJ | 8 | 8 | 8 | 1 | 1 | — | — | 8 | 8 | 8 | 7 | — | 3 | — | 3 | 7 | 7 | 2 | 1 | 3 | 3 |
Swell 3 Height (m) Direction Period (s) | — | — | — | SW 14 | SW 13 | — | — | — | S 12 | — | — | SW 11 | — | SW 8 | — | SW 8 | — | SW 13 | S 12 | — | — |
| kJ | — | — | — | 7 | 7 | — | — | — | 3 | — | — | 4 | — | 3 | — | 3 | — | 7 | 3 | — | — |
Wind waves Height (m) Direction Period (s) | NNW 4 | N 5 | NNW 5 | NNW 5 | NNW 4 | NNW 5 | NNW 5 | — | — | — | — | — | — | — | ENE 3 | ENE 5 | — | S 2 | S 4 | SSW 6 | — |
| kJ | 26 | 62 | 64 | 50 | 7 | 32 | 26 | — | — | — | — | — | — | — | 2 | 11 | — | 1 | 15 | 58 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 174 | 838 | 192 | 55 | 284 | 195 | 241 | 284 | 163 | 208 | 292 | 163 | 246 | 249 | 249 | 381 | 322 | 267 | 286 | 186 | 8 |
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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