Thermopylae Surf Forecast

/ Cape Town (69 surf breaks) /

South Africa (273 surf breaks) / Lat Long: (33.90° S 18.40° E)

Surf Forecasts:

Thermopylae surfForecast / Cape Town / South Africa

12 Day Weather and Surf, issued 1 am Tuesday 16 Sep 2025 SAST

Forecast update in hr min s Forecast update imminent

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

Today's Thermopylae sea temperature is 15.0° C
(Which is slightly cooler than normal)

Best Forecast Surf Conditions for Thermopylae this week:

The surf forecast for Thermopylae over the next 12 days: The first swell (rated 1 star or higher) is forecast to arrive on Wednesday (Sep 17) at 5AM. The primary swell is predicted to be 3.0m and 12s period with a secondary swell of 2.0m and 11s. The wind is predicted to be glassy as the swell arrives.

The most powerful waves expected at Thermopylae in the next 12 days are 5.0m 12s and forecast to arrive on Tuesday (Sep 16) at 8AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.7m 6s period and expected on Sunday (Sep 21) at 8PM.

Wave Type	Time (SAST) & Date	Wave Height & Period
Next good surf (1 star+)	5AM (Wed 17th Sep)	10ft (3.0m) 12s
Best Surf	5AM (Wed 17th Sep)	10ft (3.0m) 12s
Most Powerful	8AM (Tue 16th Sep)	16ft (5.0m) 12s

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

Updates in hr min s Forecast update imminent

12 Days Hourly

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	Short Range Forecast Mostly dry. Very mild (max 15°C on Thu afternoon, min 12°C on Tue night). Wind will be generally light.									Days 3-6 Weather Summary Light rain (total 2mm), mostly falling on Sun night. Very mild (max 18°C on Sun afternoon, min 12°C on Fri morning). Wind will be generally light.
	Tuesday 16			Wednesday 17			Thursday 18			Friday 19			Saturday 20			Sunday 21			Monday 22
	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night	AM	PM	Night
Rating (10 max)	4	3	4	5	3	4	4	1	2	3	1	2	1	0	1	1	0	0	0	1	1
Swell Height Map See all maps
Wave Height (m) & direction (?)	WSW	WSW	SSW	SSW	SSW	SSW	SSW	S	S	S	SSW	SSW	SSE	SSE	SSE	SSE	SW	SW	S	SW	SW
Period(s) (?)	12	12	12	12	12	12	11	11	11	11	10	10	12	11	11	13	12	12	6	13	12
Wave Graph (?)
Energy (?)	5584	3993	3668	3180	2471	1598	1139	897	837	693	470	361	375	310	185	163	40	48	192	204	163
Wind (km/h)	SW	SSW	S	SW	SW	WSW	NW	S	SE	SSE	S	SSE	SSW	S	SSE	SSW	SSW	NW	W	W	WSW
Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy	cross- on	cross- on	cross	cross- on	cross- on	glass	glass	cross	cross- off	cross- off	cross	glass	cross- on	cross	cross- off	glass	cross	cross- on	on	on	glass
High Tide / height (m)	11:43AM 1.33		12:16AM 1.36	12:51PM 1.46		1:15AM 1.46	1:36PM 1.59		1:56AM 1.56		2:12PM 1.69	2:31AM 1.63		2:43PM 1.76	3:01AM 1.67		3:12PM 1.80	3:29AM 1.69		3:40PM 1.80	3:55AM 1.69
Low Tide / height (m)		6:10PM 0.73		6:37AM 0.64	7:12PM 0.60		7:26AM 0.54	7:55PM 0.48		8:03AM 0.46		8:30PM 0.40	8:35AM 0.40		8:59PM 0.35	9:03AM 0.36		9:26PM 0.32	9:29AM 0.35		9:51PM 0.32

	Tuesday 16			Wednesday 17			Thursday 18			Friday 19			Saturday 20			Sunday 21			Monday 22
Sunrise	6:45	-	-	6:43	-	-	6:41	-	-	6:41	-	-	6:39	-	-	6:37	-	-	6:35	-	-
Sunset	-	6:37	-	-	6:37	-	-	6:38	-	-	6:39	-	-	6:39	-	-	6:40	-	-	6:42	-

Rain (mm)	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	2	3	-	1
Temp. °C	14	14	13	14	14	13	14	15	14	15	17	17	16	17	15	16	18	16	15	15	15
Feels °C (?)	9	9	9	11	10	9	13	12	10	13	15	16	14	14	13	15	17	14	11	12	13

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 Cape Town

Wind Update Continuing clean conditions at Thermopylae (light winds from the E at Observatory wx 8 km from Thermopylae). 4.4m 12s groundswell from the WSW with a 4.0m 12s groundswell from the SW. 2 swells combining so expect closeout sets.
22 minutes ago Thermopylae

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Actual: 22 min ago

6 km/h

Clean

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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 Thermopylae 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 Thermopylae Surf forecast

The above surf forecast table for Thermopylae provides essential information for determining whether the surfing conditions will be good over the next 12 days. A general guide to surfing at Thermopylae can be found by selecting the local surf guide option on the grey menu. Our Thermopylae 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 (Thermopylae) 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 Thermopylae 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 Cape Town? If you are looking for accommodation near Thermopylae, camping, hotels and holiday cottages in Cape Town, consider staying in Cape Town which is 8 km (5 miles) away. Other places in and around Cape Town where you can find information about places to rent, and car hire include Robben Island which is 11 km (7 miles) away, Bellville, Atlantis and Kayamnandi.