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The Knap Surf Forecast
/ Wales – South East (14 surf breaks) /
Surf Forecasts:
The Knap surfForecast / Wales – South East / UK
16 Day Weather and Surf, issued 12 pm Sunday 17 May 2026 BSTForecast update in hr min s Forecast update imminent
Today's The Knap sea temperature is
12.6° C
(Which is 1.2°C warmer than normal for this time of year)Best Forecast Surf Conditions for The Knap this week:
The most powerful waves expected at The Knap in the next 16 days are 0.7m 13s and forecast to arrive on Wednesday (May 20) at 1PM. Winds are predicted to be cross-onshore at the time the swell arrives.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1PM (Wed 20th May) | 2.5ft (0.7m) 13s |
Table - best surf conditions forecast for The Knap over the next 16 days.
Updates in hr min s Forecast update imminent
Short Range ForecastHeavy rain (total 31mm), heaviest during Mon night. Very mild (max 14°C on Tue morning, min 9°C on Sun night). Winds increasing (light winds from the WSW on Sun night, strong winds from the WSW by Tue afternoon). | Days 4-6 Weather SummaryMostly dry. Warm (max 21°C on Fri morning, min 13°C on Wed night). Winds decreasing (fresh winds from the W on Wed afternoon, calm by Fri night). | ||||||||||||||||||||
Sunday 17 | Monday 18 | Tuesday 19 | Wednesday 20 | Thursday 21 | Friday 22 | Saturday 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 |  |  |  |  |  |  |  | ||||||||||||||
W 7 | W 6 | W 6 | W 7 | W 7 | W 6 | WSW 7 | W 5 | WSW 9 | WSW 10 | W 13 | W 12 | WSW 11 | WSW 11 | WSW 10 | WSW 10 | WSW 12 | WSW 11 | WSW 10 | WSW 10 | W 10 | |
14 | 13 | 12 | 38 | 23 | 7 | 5 | 27 | 59 | 139 | 166 | 72 | 43 | 22 | 22 | 21 | 26 | 23 | 20 | 10 | 8 | |
Wind (km/h) | |||||||||||||||||||||
cross | cross-on | cross-on | cross-on | cross-on | cross-on | on | cross-on | on | cross-on | cross-on | on | on | cross-on | cross | cross-on | cross-on | glassy | cross-off | cross-off | cross-off | |
High Tide | 8:06PM11.90m | 8:28AM11.82m | 8:50PM11.95m | 9:13AM11.62m | 9:36PM11.72m | 10:00AM11.17m | 10:24PM11.25m | 10:51AM10.54m | 11:16PM10.62m | 11:46AM9.83m | 00:14AM9.95m | 12:49PM9.19m | 1:20AM9.40m | ||||||||
Low Tide | 1:51PM0.78m | 2:14AM0.74m | 2:33PM0.75m | 2:58AM0.79m | 3:17PM0.98m | 3:43AM1.09m | 4:03PM1.43m | 4:33AM1.59m | 4:52PM2.04m | 5:27AM2.21m | 5:48PM2.69m | 6:29AM2.81m | 6:52PM3.26m | ||||||||
 | |  |  | |  | |  |  |  | |  | | | | | | | | |  | |
 | 5:18 | — | — | 5:18 | — | — | 5:16 | — | — | 5:15 | — | — | 5:13 | — | — | 5:13 | — | — | 5:11 | — | — |
 | — | — | 9:00 | — | — | 9:00 | — | — | 9:02 | — | — | 9:04 | — | — | 9:05 | — | — | 9:07 | — | — | 9:07 |
— | — | 8 | 3 | 2 | 13 | 1 | — | 4 | — | — | — | — | — | — | — | — | — | — | 1 | 2 | |
Temp °C | 12 | 12 | 10 | 12 | 13 | 13 | 14 | 14 | 13 | 16 | 16 | 14 | 18 | 20 | 16 | 21 | 20 | 18 | 21 | 24 | 23 |
6 | 6 | 5 | 7 | 9 | 8 | 9 | 6 | 7 | 11 | 10 | 13 | 18 | 19 | 14 | 20 | 20 | 17 | 21 | 25 | 24 | |
Swell 1 Height (m) Direction Period (s) | W 7 | — | W 6 | — | W 7 | W 6 | WSW 7 | — | — | — | — | W 12 | WSW 11 | WSW 11 | WSW 10 | WSW 10 | WSW 12 | WSW 11 | WSW 10 | WSW 10 | W 10 |
 kJ | 14 | — | 12 | — | 23 | 7 | 5 | — | — | — | — | 72 | 43 | 22 | 22 | 21 | 26 | 23 | 20 | 10 | 8 |
Swell 2 Height (m) Direction Period (s) | W 14 | — | W 11 | — | — | W 10 | — | — | — | — | — | — | — | — | — | WSW 13 | — | — | — | — | — |
| kJ | 4 | — | 10 | — | — | 2 | — | — | — | — | — | — | — | — | — | 16 | — | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | W 12 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 3 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | W 6 | — | W 7 | — | — | SSW 3 | W 5 | WSW 9 | WSW 10 | W 13 | — | — | — | — | — | — | — | — | — | — |
| kJ | — | 13 | — | 38 | — | — | 1 | 27 | 59 | 139 | 166 | — | — | — | — | — | — | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 325 | 344 | 301 | 145 | 143 | 479 | 477 | 309 | 301 | 301 | 208 | 85 | 14 | 14 | 14 | 25 | 61 | 22 | 14 | 14 | 14 |
Best forecast wave conditions in Wales - South East | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
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Live Wave Height (m)
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FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our The Knap surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
Information about the The Knap Surf forecast
The above surf forecast table for The Knap provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at The Knap can be found by selecting the local surf guide option on the grey menu. Our The Knap 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 (The Knap) 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 The Knap 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.
The Knap is 2 km (1 miles) from Barry. If you plan a holiday in Wales - South East, look for hotels and other accommodation in Barry. Barry has rooms for a wide range of budgets as well as car hire and transport links.
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