Portstewart Strand Surf Forecast

/ Londonderry (4 surf breaks) /

Ireland (149 surf breaks) / Lat Long: (55.17° N 6.75° W)

Surf Forecasts:

Portstewart Strand surfForecast / Londonderry / Ireland

12 Day Weather and Surf, issued 6 pm Wednesday 17 Sep 2025 BST

Forecast update in hr min s Forecast update imminent

Portstewart Strand surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.

Today's Portstewart Strand sea temperature is 15.4° C
(Which is 1.6°C warmer than normal for this time of year)

Best Forecast Surf Conditions for Portstewart Strand this week:

The surf forecast for Portstewart Strand over the next 12 days: The first swell (rated 1 star or higher) is forecast to arrive on Thursday (Sep 18) at 4PM. The primary swell is predicted to be 1.2m and 10s period with a secondary swell of 0.2m and 14s. The wind is predicted to be offshore as the swell arrives.

The most powerful waves expected at Portstewart Strand in the next 12 days are 3.0m 9s and forecast to arrive on Saturday (Sep 20) at 1PM. 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 3s period and expected on Thursday (Sep 18) at 7AM.

Wave Type	Time (BST) & Date	Wave Height & Period
Next good surf (1 star+)	4PM (Thu 18th Sep)	4ft (1.2m) 10s
Best Surf	10AM (Sat 20th Sep)	10ft (3.0m) 8s
Most Powerful	1PM (Sat 20th Sep)	10ft (3.0m) 9s

Table - best surf conditions forecast for Portstewart Strand over the next 12 days.

Updates in hr min s Forecast update imminent

12 Days Hourly

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	Short Range Forecast Light rain (total 8mm), mostly falling on Thu afternoon. Very mild (max 17°C on Thu night, min 11°C on Fri night). Winds decreasing (fresh winds from the SW on Wed night, light winds from the ENE by Sat morning).											Days 3-6 Weather Summary Moderate rain (total 16mm), heaviest on Sat night. Very mild (max 13°C on Sat afternoon, min 9°C on Sat night). Mainly strong winds.
	Wed 17		Thursday 18			Friday 19			Saturday 20			Sunday 21			Monday 22			Tuesday 23
	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM
Rating (10 max)	0	0	0	2	1	0	0	1	!	4	0	0	0	0	0	0	0	0	0	1	0
Swell Height Map See all maps
Wave Height (m) & direction (?)	WNW	WNW	WNW	NW	NNW	NNW	WNW	WNW	NNW	N	N	N	N	N	N	NNW	NNW	NNW	NNW	WNW	NW
Period(s) (?)	9	14	12	10	12	9	11	11	8	8	8	8	7	7	6	5	5	6	6	12	7
Wave Graph (?)
kJ (?)	28	1143	647	286	440	69	102	130	1118	1021	577	585	392	212	73	45	43	145	80	58	12
Wind (km/h)	SW	SW	SW	SSE	S	SW	SSW	SSW	SW	E	NNE	NNE	NNE	NNE	NNE	N	NNW	N	N	NNW	WSW
Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy	cross	cross	cross	off	cross- off	cross- off	cross- off	cross- off	cross	cross- off	cross	cross- on	cross	cross	cross	cross- on	on	cross- on	cross- on	glass	cross
High Tide / height (m)	4:28PM 1.52		4:55AM 1.29	5:15PM 1.69		5:31AM 1.41	5:51PM 1.82		6:03AM 1.51	6:23PM 1.90		6:32AM 1.59	6:52PM 1.94		7:00AM 1.65		7:19PM 1.93	7:27AM 1.68		7:45PM 1.87	7:53AM 1.69
Low Tide / height (m)		11:15PM 0.41	11:01AM 0.38		11:55PM 0.29	11:40AM 0.23		12:27AM 0.21	12:13PM 0.13		12:55AM 0.16	12:43PM 0.06		1:20AM 0.13		1:12PM 0.04	1:44AM 0.13		1:40PM 0.06	2:07AM 0.17

	Wed 17		Thursday 18			Friday 19			Saturday 20			Sunday 21			Monday 22			Tuesday 23
Sunrise	-	-	7:03	-	-	7:05	-	-	7:07	-	-	7:09	-	-	7:11	-	-	7:13	-	-	7:13
Sunset	7:39	-	-	7:37	-	-	7:35	-	-	7:31	-	-	7:29	-	-	7:27	-	-	7:23	-	-

Rain (mm)	-	-	-	6	2	-	-	-	-	3	10	-	-	-	-	-	3	-	-	-	-
Temp. °C	16	14	15	13	17	15	15	13	14	13	10	11	12	11	11	12	13	12	12	11	11
Feels °C (?)	10	7	12	11	16	11	12	10	13	10	2	2	4	3	5	6	8	7	8	9	10

Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)

Recent Eyeball Surf Reports for Londonderry

Wind Update Still cross-shore at Portstewart Strand (strong winds from the SW at Magilligan Number 2 13 km from Portstewart Strand). 2.8m 3s local chop from the SW with a 1.8m 15s groundswell from the NW. 2 swells combining so expect closeout sets.
42 minutes ago Portstewart Strand

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Actual: 42 min ago

39 km/h

Cross-Shore

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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 Portstewart Strand 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 Portstewart Strand Surf forecast

The above surf forecast table for Portstewart Strand provides essential information for determining whether the surfing conditions will be good over the next 12 days. A general guide to surfing at Portstewart Strand can be found by selecting the local surf guide option on the grey menu. Our Portstewart Strand 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 (Portstewart Strand) 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 Portstewart Strand 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 Londonderry? If you are looking for accommodation near Portstewart Strand, camping, hotels and holiday cottages in Londonderry, consider staying in Coleraine which is 6 km (4 miles) away. Other places in and around Londonderry where you can find information about places to rent, and car hire include Ballycastle which is 32 km (20 miles) away, Ballypatrick, Derry and Londonderry County Borough.