Surf Forecasts:
Onrus surf forecast from 20 Aug 2026:
- Best quality surf: Thursday 20 Aug, 8AM (local time) - 11ft (3.5m), 13s period, SW swell with cross-shore winds.
- Most powerful swell: Thursday 20 Aug, 8AM (local time) - 11ft (3.5m), 13s period, SW swell with 3,697 kJ wave energy.
- Next surfable swell (1★+): Thursday 20 Aug, 8AM (local time) - 11ft (3.5m), 13s period with SW swell.
Best Forecast Surf Conditions for Onrus this week:
The surf forecast for Onrus over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Thursday (Aug 20) at 8AM. The primary swell is predicted to be 3.5m and 13s period. The wind is predicted to be cross-shore as the swell arrives.
The most powerful waves expected at Onrus in the next 16 days are 3.5m 13s and forecast to arrive on Thursday (Aug 20) at 8AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.5m 3s period and expected on Saturday (Aug 22) at 2PM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8AM (Thu 20th Aug) | 11ft (3.5m) 13s |
| Best Surf | 8AM (Thu 20th Aug) | 11ft (3.5m) 13s |
| Most Powerful | 8AM (Thu 20th Aug) | 11ft (3.5m) 13s |
Table - best surf conditions forecast for Onrus over the next 16 days.
The Lowdown
Alright mate, Rusty here. Let's get into it.
The next swell train is a solid one, but it's a bit of a mixed bag for a while. The big news is a significant pulse of SW groundswell that's going to be cranking, but it's going to be way too much for our main spot, Onrus (reef), for a few days. After that, things get cleaner and more manageable.
The first real action is on Thursday, the 20th of August. Onrus is showing a massive 10ft SW swell with a period of 13 seconds, and the combined energy is a massive 3475. That's a lot of power. The problem is, it's predicted to be too big for this break. The saving grace is the wind is glassy (ESE at 3 mph) in the morning, so it's worth a look if you're an expert and know the reef well. The water is 58°, which is a bit colder than normal for this time of year.
Friday, the 21st, the swell drops to 6ft, but the wind is a cross-onshore choppy mess, so it's not worth paddling out.
Saturday, the 22nd, offers a bit of hope. The swell is a smaller 4ft to 5ft from the SSW, with a period of 11-12 seconds. The wind swings offshore to a WNW, giving us clean conditions. The combined energy is still moderate (631-618). It's not the best swell, but it'll be clean.
Sunday, the 23rd, the swell jumps back up to 8ft, but the wind is onshore, creating choppy, messy surf. It's a no-go.
The start of the next week, Monday the 24th and Tuesday the 25th, is a write-off with onshore winds and lumpy, choppy conditions.
Then, finally, Wednesday the 26th of August, things turn around. The swell drops to a clean 5ft to 6ft from the WSW, with a 12-13 second period. The wind is offshore or glassy, giving us clean surf. The combined energy is moderate (962-855). This is the best window for intermediate surfers, with good shape and no crowds for a reef break.
Thursday the 27th is a bit smaller (4ft), still clean in the morning, but the afternoon gets messy.
The week after that is a mix of too much swell and strong onshore winds, with a few clean windows between the 1st and 2nd of September. Thursday, the 3rd of September, looks promising for experienced surfers with an 8ft swell and glassy conditions, and Friday, the 4th of September, has a similar 8ft swell with glassy conditions, which is excellent for experts.
So, the standout is clear: Wednesday the 26th of August. Get on it. The rest is either too big, too windy, or just average.
Rusty.
Short Range ForecastMostly dry. Very mild (max 19°C on Fri afternoon, min 10°C on Thu night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 23°C on Tue afternoon, min 9°C on Mon night). Wind will be generally light. | ||||||||||||||||||||
Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | |||||||||||||||
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) | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | WSW 11 | SSW 12 | SW 11 | SW 11 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SW 15 | SW 14 | SW 13 | WSW 13 | WSW 13 | SW 12 | SW 11 |
Wave Graph | |||||||||||||||||||||
3475 | 2369 | 1422 | 882 | 387 | 317 | 458 | 606 | 1017 | 1756 | 1584 | 1029 | 882 | 382 | 936 | 1657 | 1200 | 820 | 610 | 855 | 595 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | cross-on | cross-on | cross-on | on | cross-off | cross-off | cross-off | glassy | on | cross-on | cross-on | on | on | cross-on | cross-on | cross-on | cross | cross-off | glassy | cross-off |
High Tide | 8:25PM1.07m | 9:40AM0.94m | 10:21PM1.01m | 11:56AM0.98m | 00:08AM1.06m | 1:01PM1.09m | 1:04AM1.17m | 1:39PM1.22m | 1:42AM1.27m | 2:10PM1.34m | 2:15AM1.37m | 2:38PM1.46m | 2:45AM1.46m | ||||||||
Low Tide | 1:50PM0.65m | 3:11AM0.66m | 3:39PM0.74m | 5:33AM0.65m | 6:08PM0.70m | 6:49AM0.56m | 7:10PM0.59m | 7:30AM0.44m | 7:48PM0.48m | 8:02AM0.33m | 8:19PM0.37m | 8:29AM0.23m | 8:48PM0.27m | ||||||||
7:16 | — | — | 7:16 | — | — | 7:15 | — | — | 7:13 | — | — | 7:13 | — | — | 7:11 | — | — | 7:09 | — | — | |
— | 6:15 | — | — | 6:15 | — | — | 6:16 | — | — | 6:17 | — | — | 6:17 | — | — | 6:19 | — | — | 6:20 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 14 | 15 | 13 | 14 | 19 | 15 | 17 | 17 | 15 | 15 | 17 | 13 | 15 | 17 | 13 | 16 | 23 | 23 | 27 | 27 | 17 |
Feels °C | 13 | 13 | 10 | 10 | 16 | 13 | 13 | 13 | 14 | 14 | 15 | 11 | 13 | 14 | 9 | 10 | 19 | 19 | 23 | 25 | 16 |
Swell 1 Height (m) Direction Period (s) | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SSW 10 | SSW 12 | SW 11 | SW 11 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SW 15 | SW 14 | SW 13 | WSW 13 | WSW 13 | SW 12 | SW 11 |
3475 | 2369 | 1422 | 882 | 387 | 274 | 458 | 606 | 1017 | 1756 | 1584 | 1029 | 882 | 382 | 936 | 1657 | 1200 | 820 | 610 | 855 | 595 | |
Swell 2 Height (m) Direction Period (s) | — | — | — | SSW 11 | WSW 11 | WSW 11 | WSW 10 | SW 17 | WSW 14 | SW 14 | — | — | SSW 15 | WSW 11 | SW 10 | SW 17 | SW 16 | SSW 13 | SSW 12 | — | SW 20 |
— | — | — | 452 | 379 | 317 | 173 | 12 | 367 | 382 | — | — | 42 | 331 | 298 | 400 | 471 | 249 | 322 | — | 15 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | SSW 14 | — | — | — | — | — | — | — | SW 14 | WSW 11 | — | SSW 9 | SE 5 | SE 6 | ESE 7 | SW 11 |
— | — | — | — | — | 108 | — | — | — | — | — | — | — | 206 | 156 | — | 29 | 14 | 30 | 26 | 97 | |
Wind waves Height (m) Direction Period (s) | — | — | — | ESE 3 | SE 4 | — | WNW 3 | — | — | — | SE 3 | — | — | SSE 4 | E 3 | ESE 4 | ESE 5 | ENE 3 | — | — | — |
— | — | — | 3 | 12 | — | 1 | — | — | — | 5 | — | — | 10 | 7 | 20 | 45 | 4 | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 10 | 32 | 10 | 4 | 4 | 0 | 31 | 8 | 0 | 4 | 23 | 4 | 4 | 272 | 23 | 38 | 4 | 10 | 0 | 0 | 0 |
Best forecast wave conditions in Overberg | |||||||||||||||||||||
Best forecast wave conditions in South Africa | |||||||||||||||||||||
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Information about the Onrus Surf forecast
The above surf forecast table for Onrus provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Onrus can be found by selecting the local surf guide option on the grey menu. Our Onrus 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 (Onrus) 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 Onrus 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.
Onrus is 6 km (4 miles) from Hermanus. If you plan a holiday in Overberg, look for hotels and other accommodation in Hermanus. Hermanus has rooms for a wide range of budgets as well as car hire and transport links.











