Surf Forecasts:
Crab Island surf forecast from 18 Aug 2026:
- Best quality surf: Thursday 20 Aug, 7AM (local time) - 5ft (1.5m), 7s period, W swell with cross-offshore winds.
- Most powerful swell: Thursday 20 Aug, 7AM (local time) - 5ft (1.5m), 7s period, W swell with 245 kJ wave energy.
- Next surfable swell (1★+): Wednesday 19 Aug, 1AM (local time) - 3.5ft (1.0m), 6s period with W swell.
Best Forecast Surf Conditions for Crab Island this week:
The surf forecast for Crab Island over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Wednesday (Aug 19) at 1AM. The primary swell is predicted to be 1.0m and 6s period with a secondary swell of 0.1m and 17s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Crab Island in the next 16 days are 1.5m 7s and forecast to arrive on Thursday (Aug 20) at 7AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 4s period and expected on Thursday (Aug 20) at 7PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 1AM (Wed 19th Aug) | 3.5ft (1.0m) 6s |
| Best Surf | 7AM (Thu 20th Aug) | 5ft (1.5m) 7s |
| Most Powerful | 7AM (Thu 20th Aug) | 5ft (1.5m) 7s |
Table - best surf conditions forecast for Crab Island over the next 16 days.
The Lowdown
Alright, folks, Rusty here. Let’s break down the next couple of weeks for Crab Island. The first week is a total dud. We got a bunch of weak, short-period swell and a ton of cross-shore wind just chopping everything up. There’s one bright spot: the morning of Thursday, August 20th. The wind eases off to a light cross-offshore, and the surf cleans up. We’re looking at a 4ft west-southwest swell with a period of 7 seconds. The combined energy is 216, so it’s got a little punch for such a short period. It won’t be epic, but it’ll be the only clean surf you’ll see for days. Go get a few if you can.
From Friday the 21st, it just flat-lines for a solid stretch. We’re talking knee-high slop and onshores. There’s a proper gap of several days where you won’t even bother waxing up. Wait it out.
The second week is where the story changes. A solid west-southwest groundswell builds in around the end of the month. The 31st of August has some size, about 7ft, but it’s rocky in the water with a cross-onshore wind. It’s messy and not good for surfing. Then the 1st of September remains big, around 7ft, but the wind is still on it, making it a ropy, lumpy mess. The energy is massive, peaking at 1410 on Tuesday morning, but it’s all for nothing if the wind’s howling.
Now, the one to watch is the morning of Wednesday, September 2nd. The wind finally drops to a light cross-offshore. That’s the key. We get a clean 6ft west-southwest swell with a period of 8 seconds and a strong combined energy of 521. The guidance is saying "very good surf conditions." This is it. The stars align. It’s a proper reef break, and with that much swell, it’s for experienced surfers only. But if you can handle it, it’s going to be firing. Mark that date, but remember it’s still a week out, so we’ll have to see how it shapes up.
The rest of that week stays small and average. So, the plan is simple: skip the first week, and start getting excited about the 2nd.
Rusty out.
Short Range ForecastLight rain (total 8mm), mostly falling on Tue night. Very mild (max 19°C on Tue morning, min 14°C on Wed night). Mainly fresh winds. | Days 4-6 Weather SummarySome drizzle, heaviest during Fri afternoon. Very mild (max 19°C on Sun afternoon, min 12°C on Thu night). Wind will be generally light. | ||||||||||||||||||||
Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 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) | W 7 | W 6 | W 6 | W 6 | WSW 6 | W 7 | WSW 7 | W 7 | WSW 9 | WSW 8 | W 8 | WSW 9 | WSW 10 | WSW 10 | WSW 9 | W 9 | WSW 9 | WSW 8 | WSW 8 | WSW 8 | WSW 8 |
Wave Graph  | |||||||||||||||||||||
 kJ | 130 | 81 | 78 | 78 | 131 | 212 | 208 | 181 | 101 | 53 | 33 | 25 | 18 | 18 | 8 | 8 | 8 | 8 | 8 | 7 | 7 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross | cross-off | cross | cross | cross | cross-off | cross-off | off | cross-off | cross-off | cross-off | cross | cross-off | off | off | cross-off | off | cross-on | cross | on |
High Tide | 10:41AM8.59m | 10:55PM8.48m | 11:12AM8.06m | 11:28PM7.89m | 11:51AM7.51m | 00:13AM7.29m | 12:49PM7.00m | 1:23AM6.79m | 2:19PM6.75m | 2:58AM6.69m | 3:48PM7.01m | 4:21AM7.06m | 4:55PM7.57m | ||||||||
Low Tide | 4:25AM1.75m | 4:35PM1.94m | 4:54AM2.27m | 5:08PM2.48m | 5:28AM2.83m | 5:52PM3.08m | 6:17AM3.42m | 7:01PM3.61m | 7:43AM3.84m | 8:36PM3.79m | 9:21AM3.79m | 10:00PM3.49m | 10:37AM3.32m | 11:04PM2.94m | |||||||
 | |  |  |  | | | |  | | |  | | |  | | | | |  | | |
 | 6:05 | — | — | 6:05 | — | — | 6:07 | — | — | 6:09 | — | — | 6:11 | — | — | 6:13 | — | — | 6:13 | — | — |
 | — | 8:32 | — | — | 8:30 | — | — | 8:29 | — | — | 8:27 | — | — | 8:24 | — | — | 8:22 | — | — | 8:21 | — |
mm | — | — | 2 | 2 | — | 4 | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — | — |
Temp °C | 19 | 18 | 17 | 17 | 18 | 17 | 17 | 18 | 15 | 16 | 17 | 16 | 17 | 18 | 14 | 18 | 19 | 14 | 16 | 17 | 15 |
Feels °C | 15 | 14 | 13 | 14 | 13 | 13 | 13 | 14 | 11 | 14 | 14 | 12 | 15 | 13 | 11 | 14 | 14 | 10 | 14 | 14 | 14 |
Swell 1 Height (m) Direction Period (s) | W 7 | SW 17 | W 6 | SW 16 | W 9 | SW 16 | WSW 7 | SW 14 | WSW 9 | WSW 8 | W 8 | WSW 9 | WSW 10 | WSW 10 | WSW 9 | W 9 | WSW 9 | WSW 8 | WSW 8 | WSW 8 | W 3 |
| kJ | 130 | 11 | 78 | 11 | 15 | 10 | 208 | 8 | 101 | 53 | 33 | 25 | 18 | 18 | 8 | 6 | 8 | 7 | 7 | 7 | 2 |
Swell 2 Height (m) Direction Period (s) | SW 16 | — | SW 17 | W 16 | W 16 | W 9 | SW 15 | — | SW 14 | SW 16 | SW 13 | — | SW 15 | SW 15 | WNW 4 | SW 14 | SW 14 | WNW 3 | SW 14 | SW 14 | WSW 8 |
| kJ | 11 | — | 12 | 5 | 5 | 6 | 8 | — | 8 | 10 | 7 | — | 9 | 8 | 1 | 8 | 8 | 1 | 8 | 7 | 6 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | SW 16 | — | — | SW 14 | SW 13 | SW 16 | SW 13 | — | — | SW 15 | W 15 | — | SW 14 | W 14 | — | SW 13 |
| kJ | — | — | — | — | — | 10 | — | — | 8 | 7 | 10 | 7 | — | — | 8 | 4 | — | 8 | 4 | — | 7 |
Wind waves Height (m) Direction Period (s) | — | W 6 | — | W 6 | WSW 6 | W 7 | — | W 7 | NNW 4 | — | — | — | — | — | NNW 3 | NNW 3 | — | N 3 | — | — | — |
| kJ | — | 81 | — | 78 | 131 | 212 | — | 181 | 3 | — | — | — | — | — | 1 | 1 | — | 1 | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 144 | 320 | 0 | 361 | 320 | 144 | 0 | 222 | 0 | 0 | 191 | 86 | 51 | 190 | 319 | 319 | 206 | 222 | 351 | 397 | 319 |
Best forecast wave conditions in Wales - Gower | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
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Information about the Crab Island Surf forecast
The above surf forecast table for Crab Island provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Crab Island can be found by selecting the local surf guide option on the grey menu. Our Crab 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 (Crab 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 Crab 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.
Crab Island is 8 km (5 miles) from Swansea. If you plan a holiday in Wales - Gower, look for hotels and other accommodation in Swansea. Swansea has rooms for a wide range of budgets as well as car hire and transport links.
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