Surf Forecasts:
Crab Island surf forecast from 18 Aug 2026:
- Best quality surf: Thursday 20 Aug, 7AM (local time) - 4.5ft (1.4m), 7s period, WSW swell with cross-offshore winds.
- Most powerful swell: Thursday 20 Aug, 7AM (local time) - 4.5ft (1.4m), 7s period, WSW swell with 214 kJ wave energy.
- Next surfable swell (1★+): Wednesday 19 Aug, 1AM (local time) - 3ft (0.9m), 6s period with WSW 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 0.9m 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 1.4m 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 0.4m 4s period and expected on Friday (Aug 21) at 10PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 1AM (Wed 19th Aug) | 3ft (0.9m) 6s |
| Best Surf | 7AM (Thu 20th Aug) | 4.5ft (1.4m) 7s |
| Most Powerful | 7AM (Thu 20th Aug) | 4.5ft (1.4m) 7s |
Table - best surf conditions forecast for Crab Island over the next 16 days.
The Lowdown
Alright folks, Rusty here, and I’ve gotta be straight with you from the jump: Crab Island is looking pretty grim over the next two weeks. There’s really only one or two moments where you might paddle out and feel okay about it, but the rest of the time, you’re better off finding something else to do. We’re talking about a long run of days with nothing worth getting wet for, especially from the start through the end of August.
Kicking off, Tuesday the 18th and Wednesday the 19th are just messy. Tuesday morning you’ve got a 4ft cross-off swell from the west at 7 seconds, but the combined energy is only moderate at 141 and the wave comment says poor. That afternoon and all of Wednesday it gets worse – dropping down to 3ft and 3ft, small, weak, and crossed-up. The water is reading 70°, which is a whopping 8° warmer than normal for this time of year, so it’s much warmer than usual, but it doesn’t make up for the flat, grovelly conditions.
We grind through Thursday the 20th with some clean-looking but weak 4ft cross-off swells and energy around 158-163. Still, it’s not firing. Friday the 21st gives us a tiny window – Friday morning there’s a 2ft westerly swell, glassy, clean, but the energy is only 67 and the wave comment says it’s surfable but very ordinary. That’s the best of a bad batch, really. From Friday afternoon all the way through to Monday the 24th, it’s tiny, glassy or crossed-off dribble, with swells under 1.0ft and periods up to 14 seconds, combined energy dropping into the teens and twenties. Don’t even bother.
Now, here’s the one standout in the whole outlook, but it comes with a big warning. On Tuesday the 25th, a pulse of swell pushes through, with morning heights of 7ft from the southwest at 9 seconds, and the combined energy jumps to a massive 1188. That’s strong, powerful. But the wind on that morning is a fresh cross-onshore from the ESE at 22 mph, and it’s lumpy. That’s not paddle-surfing conditions, mate, that’s kite-surfing weather. The afternoon is still 5ft but messy. This is only for the heavies, and even then, it’s onshore slop. After that, from the 26th through the 30th, it’s back to tiny, weak, and crossed-up. There’s a brief, glassy window on Saturday afternoon the 29th with 2ft but just 61 energy and the wave comment says surfable but very ordinary.
Looking into early September, Tuesday the 1st and Wednesday the 2nd are still no good – 4ft to 5ft but onshore and choppy, energy between 62 and 136. Not worth it.
Honestly, if you’re going to pick one time to go, the Friday morning of the 21st of August is your best shot. It’s small, clean, and you might catch a few ripples. For the big swell on the 25th, leave the foam board at home and bring the kite gear – the island setup with that wind is just a mess for a paddle. It’s a quiet spell for Crab Island, and that’s how it goes sometimes.
Rusty.
Short Range ForecastLight rain (total 5mm), mostly falling on Tue night. Very mild (max 19°C on Tue morning, min 12°C on Thu night). Winds increasing (light winds from the NW on Tue night, fresh winds from the W by Wed afternoon). | Days 4-6 Weather SummaryMostly dry. Very mild (max 18°C on Sun afternoon, min 13°C on Fri 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 | WSW 6 | WSW 6 | WSW 6 | WSW 5 | WSW 7 | WSW 7 | W 7 | WSW 9 | WSW 8 | WSW 8 | WSW 8 | WSW 10 | WSW 10 | W 9 | WSW 9 | WSW 9 | W 8 | W 8 | WSW 9 | WSW 4 |
Wave Graph | |||||||||||||||||||||
130 | 85 | 66 | 46 | 56 | 175 | 208 | 146 | 132 | 54 | 22 | 14 | 18 | 18 | 14 | 8 | 8 | 8 | 8 | 8 | 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 | cross-off | off | cross-off | off | cross | cross-off | cross-off | glassy | cross | off | cross-on | 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 | 4:35PM1.94m | 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 | 1 | — | 1 | — | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 19 | 18 | 18 | 18 | 17 | 16 | 16 | 18 | 15 | 16 | 17 | 14 | 14 | 17 | 15 | 17 | 18 | 17 | 17 | 18 | 16 |
Feels °C | 16 | 14 | 16 | 14 | 11 | 12 | 12 | 15 | 12 | 14 | 13 | 11 | 11 | 14 | 12 | 15 | 15 | 14 | 15 | 15 | 14 |
Swell 1 Height (m) Direction Period (s) | W 7 | SW 17 | WSW 6 | WSW 6 | W 16 | SW 16 | SW 15 | SW 14 | WSW 9 | WSW 8 | WSW 8 | WSW 8 | WSW 10 | WSW 10 | W 9 | WSW 9 | WSW 9 | WNW 4 | W 8 | WSW 9 | WSW 4 |
130 | 11 | 66 | 46 | 5 | 10 | 8 | 8 | 132 | 54 | 22 | 14 | 18 | 18 | 14 | 8 | 8 | 1 | 6 | 8 | 7 | |
Swell 2 Height (m) Direction Period (s) | SW 16 | — | SW 17 | SW 16 | — | W 9 | W 15 | SW 15 | SW 14 | SW 13 | WSW 6 | WNW 4 | SW 15 | — | SW 15 | SW 14 | SW 14 | W 8 | SW 14 | SW 14 | WSW 8 |
11 | — | 12 | 11 | — | 6 | 4 | 8 | 8 | 7 | 12 | 3 | 9 | — | 8 | 8 | 8 | 6 | 8 | 7 | 7 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | W 16 | — | SW 16 | — | — | W 14 | SW 16 | SW 13 | NNW 3 | — | SW 15 | — | — | — | SW 14 | SW 14 | — | SW 13 |
— | — | — | 5 | — | 10 | — | — | 4 | 10 | 7 | 1 | — | 8 | — | — | — | 8 | 8 | — | 7 | |
Wind waves Height (m) Direction Period (s) | — | WSW 6 | — | — | WSW 5 | WSW 7 | WSW 7 | W 7 | N 3 | — | — | — | ESE 3 | — | — | — | — | NNW 3 | — | WSW 4 | — |
— | 85 | — | — | 56 | 175 | 208 | 146 | 1 | — | — | — | 3 | — | — | — | — | 1 | — | 2 | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 144 | 320 | 0 | 251 | 320 | 82 | 49 | 49 | 0 | 0 | 262 | 20 | 51 | 153 | 319 | 73 | 202 | 86 | 374 | 437 | 364 |
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.











