Using Surf-Forecast’s Historical Surf Data To Find The Most Consistent Waves On Earth
Using our statistical data for 7000 spots dating back to 2006, we can find those waves that break the most, with the best winds.
Surf Forecasts:
Castlerock surfForecast / Londonderry / Ireland
48hr Weather and Surf, issued 5 pm Wednesday 17 Dec 2025 GMTForecast update in hr min s Forecast update imminent
Castlerock surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Castlerock sea temperature is
10.8° C
(Which is slightly warmer than usual)How big are the waves at Castlerock today?
The current surf forecast for Castlerock at 11PM is: 2.5m 20s primary swell from a Northwest direction and 0.1m 10s secondary swell from a Northeast direction (forecast issued at 05:00pm December 17). An open ocean swell of 0.5m 3s is not directed at the surf break. The wind direction is predicted to be cross-offshore.
| Time (GMT) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (17 Dec) | - | - |
| Afternoon (17 Dec) | 3ft (0.9m) | 13s |
| Evening (17 Dec) | 5.5ft (1.7m) | 14s |
Table - waves today at Castlerock. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Wednesday 17 | Thursday 18 | Friday 19 | Saturday 20 | |||||||||||||||||||||
| 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |    |    |    |    | ||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 13 | 13 | 14 | 20 | 20 | 20 | 20 | 19 | 19 | 19 | 18 | 18 | 17 | 16 | 16 | 16 | 16 | 15 | 15 | 14 | 13 | 13 | 12 | 12 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 261 | 346 | 1142 | 5358 | 8613 | 8613 | 8056 | 7202 | 6323 | 7199 | 5428 | 4185 | 3850 | 3128 | 3177 | 3543 | 3455 | 2869 | 2295 | 1536 | 1006 | 669 | 398 | 287 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | off | off | off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | cross- off | off | off | off | off | cross- off | cross- off |
High Tide / height (m) | 4:32PM 1.45 | 4:56AM 1.53 | 5:06PM 1.48 | 5:29AM 1.61 | 5:39PM 1.50 | 6:02AM 1.66 | ||||||||||||||||||
Low Tide / height (m) | 10:53PM 0.36 | 11:20AM 0.38 | 11:27PM 0.31 | 11:58AM 0.35 | 12:01AM 0.27 | |||||||||||||||||||
Wednesday 17 | Thursday 18 | Friday 19 | Saturday 20 | |||||||||||||||||||||
| Sunrise | - | - | - | - | - | - | 8:48 | - | - | - | - | - | - | - | 8:48 | - | - | - | - | - | - | - | 8:49 | - |
| Sunset | 3:56 | - | - | - | - | - | - | - | 3:56 | - | - | - | - | - | - | - | 3:57 | - | - | - | - | - | - | - |
 |  |  | |  | |  |  | |  | | | | | | | | | | | | | | | |
Rain (mm) | 1 | - | - | - | - | - | - | - | 4 | 2 | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 11 | 10 | 9 | 8 | 7 | 7 | 6 | 9 | 8 | 6 | 6 | 6 | 8 | 9 | 8 | 8 | 8 | 8 | 8 | 7 | 8 | 9 | 9 | 10 |
| Feels °C (?) | 5 | 4 | 2 | 0 | -2 | -1 | 0 | 0 | 1 | -1 | -3 | -4 | -2 | 0 | -1 | 0 | 0 | 1 | 2 | 1 | 0 | 1 | 1 | 1 |
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Castlerock 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.
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