Surf Forecasts:
Onrus surf forecast from 18 Aug 2026:
- Best quality surf: Tuesday 18 Aug, 11PM (local time) - 10ft (3.0m), 12s period, SW swell with cross-onshore 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★+): Tuesday 18 Aug, 11PM (local time) - 10ft (3.0m), 12s 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 Tuesday (Aug 18) at 11PM. The primary swell is predicted to be 3.0m and 12s period. The wind is predicted to be cross-onshore 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-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.9m 4s period and expected on Saturday (Aug 22) at 8AM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Tue 18th Aug) | 10ft (3.0m) 12s |
| Best Surf | 11PM (Tue 18th Aug) | 10ft (3.0m) 12s |
| 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 folks, Rusty here, looking at the next couple of weeks for us. The water’s sitting at 58°, which is a bit colder than we usually get this time of year, so don't forget the extra rubber.
The big story is that we’ve got a solid run of SW groundswell on the cards, but it's going to be a game of patience. The first few days are going to be a real handful with some serious size. We’re looking at a pulse of very strong wave energy (2458) hitting on Tuesday the 18th, with 10 ft of SW swell coming in at a long 13 seconds. That’s expert territory, and honestly, it’s probably going to be too big for Onrus to handle cleanly even with the offshore SSE wind. The following morning, Wednesday the 19th, the swell drops a touch to 8 ft but the wind is cross-shore, making things messy.
The real standout pops up on Thursday morning the 20th of August. The swell is still a meaty 10 ft from the SW, but the magic is in the wind – it’s dead calm, glassy, with zero wind. The wave energy is pumping hard at 3422. This is a window for the very experienced crew only; the size and the absolute glassy conditions off the E wind will make for some epic, clean faces if you can get in the right spot. The afternoon gets a little bumpy with a cross-onshore wind coming in.
After that, Friday the 21st sees the swell start to drop, but the wind is messy from the east, making it choppy. The energy is fading to moderate (833) by the afternoon. Saturday morning the 22nd is a write-off with a strong 35 km/h cross-offshore wind, but the swell is small. The next real glimmer of hope doesn't come until the middle of the next week. On Wednesday the 26th of August, in the morning, we get a clean, glassy 6 ft swell from the WSW with moderate energy (915). The wind is from the SSE, which is glassy. It's a much more manageable size, so look for a session then.
The long-range forecast is promising, but a bit of a gamble. Around Monday the 31st of August, we see a new pulse of very strong energy (3279) with an 8 ft SW swell and a very long 16-second period. The wind is looking clean and offshore from the WNW. That long period stuff is best for the point and reef, it might be a little too lined up for the beach. There’s potential for a great session for the experienced crew, but it's a ways out, so keep an eye on it.
Stay keen, and don't be afraid to sit it out if it looks too big. The good waves are coming, you just have to wait for them.
Rusty.
Short Range ForecastMostly dry. Very mild (max 16°C on Tue afternoon, min 10°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 20°C on Fri afternoon, min 11°C on Sun morning). Winds decreasing (fresh winds from the WNW on Sat morning, calm by Sun night). | |||||||||||||||||||
Tue 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | ||||||||||||||
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 12 | SW 12 | SW 12 | SW 13 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | WSW 11 | SSW 12 | SW 10 | SW 13 | SW 12 | SW 12 | WSW 12 | WSW 12 | WSW 11 | SW 14 |
Wave Graph | ||||||||||||||||||||
2458 | 2148 | 1665 | 1451 | 2132 | 3422 | 2407 | 1422 | 882 | 423 | 317 | 324 | 971 | 2574 | 1826 | 1598 | 1100 | 593 | 383 | 541 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | cross-on | cross | cross-off | cross-off | glassy | cross-on | cross-on | cross-on | cross-on | cross-off | cross-off | cross-off | glassy | cross-on | cross-on | glassy | on | cross-on | cross-on |
High Tide | 6:46PM1.33m | 7:08AM1.13m | 7:25PM1.19m | 7:59AM1.02m | 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 | |||||||
Low Tide | 1:06AM0.45m | 1:02PM0.53m | 1:50AM0.57m | 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 | ||||||||
— | — | 7:18 | — | — | 7:16 | — | — | 7:16 | — | — | 7:15 | — | — | 7:13 | — | — | 7:13 | — | — | |
6:14 | — | — | 6:15 | — | — | 6:15 | — | — | 6:15 | — | — | 6:16 | — | — | 6:17 | — | — | 6:17 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 16 | 13 | 14 | 15 | 14 | 15 | 15 | 13 | 15 | 20 | 16 | 15 | 16 | 14 | 14 | 16 | 12 | 14 | 16 | 13 |
Feels °C | 14 | 10 | 13 | 12 | 12 | 15 | 13 | 11 | 12 | 18 | 16 | 9 | 11 | 12 | 12 | 14 | 11 | 13 | 13 | 11 |
Swell 1 Height (m) Direction Period (s) | SW 13 | SW 12 | SW 12 | SW 12 | SW 13 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SSW 10 | SSW 12 | SW 10 | SW 13 | SW 12 | SW 12 | WSW 12 | WSW 12 | SSW 10 | SW 10 |
2458 | 2148 | 1665 | 1451 | 2132 | 3422 | 2407 | 1422 | 882 | 423 | 298 | 324 | 971 | 2574 | 1826 | 1598 | 1100 | 593 | 340 | 377 | |
Swell 2 Height (m) Direction Period (s) | E 11 | E 10 | E 10 | E 10 | — | — | — | — | SSW 11 | WSW 11 | WSW 11 | WSW 6 | WSW 17 | — | — | — | — | SSW 10 | WSW 11 | SW 14 |
9 | 2 | 2 | 2 | — | — | — | — | 436 | 379 | 317 | 48 | 30 | — | — | — | — | 245 | 383 | 541 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | WSW 10 | — | — | — | — | — | — | SSW 14 | W 11 |
— | — | — | — | — | — | — | — | — | — | — | 125 | — | — | — | — | — | — | 75 | 238 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | E 3 | ESE 4 | — | NW 4 | — | — | — | — | — | — | — | — |
— | — | — | — | — | — | — | — | 5 | 31 | — | 14 | — | — | — | — | — | — | — | — | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 32 | 10 | 32 | 0 | 0 | 10 | 83 | 10 | 4 | 4 | 31 | 60 | 17 | 10 | 10 | 32 | 0 | 4 | 4 | 10 |
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.











