Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 18 Jul 2026:
- Most powerful swell: Saturday 25 Jul, 7AM (local time) - 2ft (0.6m), 4s period, W swell with 10 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 0.6m 4s and forecast to arrive on Saturday (Jul 25) at 7AM. 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 (Jul 22) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 7AM (Sat 25th Jul) | 2ft (0.6m) 4s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, let me have a look at what we’ve got for Trearddur Bay (Holy Island). Straight up, I hate to be the bearer of bad news, but this 16-day window is looking pretty flat. The only bump on the charts is tiny, short-period dribble, and it’s paired with winds that are never truly offshore. The water’s sitting at 62°F – a touch warmer than usual for this time of year, which is nice for a paddle, but that’s about the only positive.
From Friday 17th July right through to Saturday 1st August, there’s nothing that’s going to get you out of bed. The first few days – Friday 17th, Saturday 18th, Sunday 19th – we’re looking at 0.3 ft of swell, period around 11-12 seconds, but that’s just not enough to push through. The combined swell energy is a tiny 10 (Friday afternoon) or less. Winds are cross-off or cross, so the surface is clean, but there’s no wave to ride. It’s a glassy lake with a ripple.
Then from Monday 20th to Thursday 23rd, the swell disappears completely – zeros across the board. Combined energy is 0. That’s a dead zone. Friday 24th sees a tiny 0.3 ft from the south, period 13 seconds, but it’s cross-on from the west, so any hope of a clean face is gone. Same story Saturday 25th: 3 ft from the west-northwest, but period is a poor 4 seconds – that’s windswell, not proper groundswell – and the wind is onshore from the south-southwest at 16 mph. The combined energy is only 25, so it’s weak and messy. Not worth paddling out.
Sunday 26th: back to 0.3 ft, clean but tiny. Monday 27th is the biggest we see: 4 ft from the west, period 5 seconds, combined energy 88. Sounds promising for a second, but the wind is cross-on from the west-northwest at 12 mph, making it choppy. That short period means the waves are crumbly, and with a beach break like Trearddur Bay, it’s not going to hold shape. Too big for beginners? Maybe borderline, but not quality. Tuesday 28th onwards fades back to 0.3-1 ft with poor winds.
The last few days – 29th July to 1st August – are a mix of cross-off and cross-on, but the swell is negligible. Saturday 1st August has 3 ft from the west-northwest with a fresh cross-on breeze – lumpy, messy, not worth it.
This is a spot that’s inconsistent at the best of times, and a blank run like this is normal for the area. The forecasts can change, but right now, I’d leave the board in the car and maybe go for a walk along the shore. Nothing to get excited about.
Rusty
Short Range ForecastMostly dry. Very mild (max 18°C on Fri night, min 13°C on Fri night). Mainly fresh winds. | Days 4-6 Weather SummaryMostly dry. Very mild (max 17°C on Thu afternoon, min 12°C on Tue night). Mainly fresh winds. | ||||||||||||||||||||
Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | Thursday 23 | Friday 24 | |||||||||||||||
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) | S 11 | SW 11 | S 11 | S 11 | S 10 | S 10 | NNW 5 | NNW 5 | NNW 5 | NNW 5 | N 5 | N 6 | NNW 6 | NNW 6 | N 6 | NNW 6 | N 5 | NNW 5 | S 13 | S 13 | SW 3 |
Wave Graph  | |||||||||||||||||||||
 kJ | 2 | 5 | 2 | 2 | 2 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 3 | 3 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross | 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 | on | cross-on | on |
High Tide | 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 | 7:10AM4.28m | 7:50PM4.38m | ||||||||
Low Tide | 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 | 1:29PM2.12m | 2:05AM2.17m | |||||||
 | |  |  | | | | |  | | | | | | | | | | | |  | |
 | 5:11 | — | — | 5:13 | — | — | 5:15 | — | — | 5:16 | — | — | 5:18 | — | — | 5:20 | — | — | 5:20 | — | — |
 | — | — | 9:35 | — | — | 9:34 | — | — | 9:32 | — | — | 9:30 | — | — | 9:30 | — | — | 9:28 | — | — | 9:27 |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 7 |
Temp °C | 13 | 16 | 17 | 15 | 16 | 16 | 13 | 16 | 16 | 15 | 16 | 14 | 15 | 16 | 15 | 15 | 17 | 16 | 16 | 18 | 17 |
Feels °C | 9 | 12 | 15 | 12 | 13 | 12 | 10 | 13 | 13 | 12 | 14 | 12 | 11 | 11 | 11 | 12 | 16 | 14 | 14 | 15 | 14 |
Swell 1 Height (m) Direction Period (s) | SW 6 | SW 6 | S 11 | S 11 | S 10 | S 10 | — | — | — | — | — | — | — | — | — | — | N 5 | NNW 5 | N 4 | — | — |
| kJ | 1 | 1 | 2 | 2 | 2 | 2 | — | — | — | — | — | — | — | — | — | — | 18 | 7 | 1 | — | — |
Swell 2 Height (m) Direction Period (s) | S 11 | SW 11 | S 5 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | S 13 | S 13 | — |
| kJ | 2 | 5 | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 3 | 3 | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | NNW 5 | NNW 6 | N 5 | NNW 4 | NNW 4 | N 4 | NNW 5 | NNW 5 | NNW 5 | NNW 5 | N 5 | N 6 | NNW 6 | NNW 6 | N 6 | NNW 6 | — | — | — | SW 2 | SW 3 |
| kJ | 46 | 104 | 11 | 5 | 5 | 10 | 47 | 33 | 45 | 32 | 15 | 106 | 130 | 150 | 85 | 50 | — | — | — | 1 | 3 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 284 | 284 | 267 | 284 | 328 | 273 | 284 | 318 | 273 | 284 | 358 | 59 | 59 | 59 | 59 | 267 | 292 | 273 | 251 | 235 | 251 |
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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