Surf Forecasts:
Onrus surf forecast from 18 Aug 2026:
- Best quality surf: Tuesday 18 Aug, 5PM (local time) - 10ft (3.0m), 13s period, SW swell with onshore winds.
- Most powerful swell: Saturday 22 Aug, 8PM (local time) - 13ft (4.0m), 13s period, SW swell with 5,753 kJ wave energy.
- Next surfable swell (1★+): Tuesday 18 Aug, 5AM (local time) - 6.5ft (2.0m), 13s period with WSW 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 5AM. The primary swell is predicted to be 2.0m and 13s period with a secondary swell of 1.2m and 14s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Onrus in the next 16 days are 4.0m 13s and forecast to arrive on Saturday (Aug 22) at 8PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.9m 6s period and expected on Saturday (Aug 22) at 8AM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5AM (Tue 18th Aug) | 6.5ft (2.0m) 13s |
| Best Surf | 5PM (Tue 18th Aug) | 10ft (3.0m) 13s |
| Most Powerful | 8PM (Sat 22nd Aug) | 13ft (4.0m) 13s |
Table - best surf conditions forecast for Onrus over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s break down this next stretch of swell. We’ve got a lot of energy hitting the water over the next two weeks, but it’s a real mixed bag. Plenty of power, but you gotta pick your moments, or you’ll get eaten alive.
The name of the game here is size. There’s heaps of it, but a lot of it is just too much for Onrus. We’ll see some windows of perfection, but also some days that are just out of control. The first chance to get wet is on Tuesday the 18th , but it’s not looking great. The morning has a clean 2.4m SW swell with a 12-second period, but the SE wind is right onshore and it’s messy. The energy is strong at 2650, but the surface won't be pretty. The afternoon is a write-off – the swell jumps to a 3.0m, and that’s just too big for this break.
Wednesday the 19th is the first real call. The swell settles to a very solid 2.4m from the SW, but the key is a light cross-offshore breeze. The energy is still pumping at 1665, and the conditions are marked as excellent for experienced surfers. This is a proper window for a reef break like this. The afternoon holds another clean 2.3m swell with light W winds. This is a full day of good surfing.
Thursday the 20th is a no-go. The swell explodes to a 3.5m giant in the morning with a cross-on breeze. Way too big. The afternoon eases to 3.0m but it’s still onshore. Give it a miss.
Friday the 21st is a letdown. The swell drops to 1.9m but it’s choppy and cross-onshore. The afternoon is even smaller and wind is up. Not worth paddling out.
Saturday the 22nd has a morning of small, clean but weak surf with a strong offshore wind. The afternoon brings a 3.0m swell with a good offshore wind, but it’s too big again.
Sunday the 23rd is the other jewel in this forecast. The morning brings a 2.5m SW swell, but the wind is dead glassy. Zero wind. The energy is a strong 1913, and the conditions are predicted to be excellent. This will be a powerful, clean, perfect morning. The afternoon drops to 1.9m and gets a light onshore wind, so the morning is the move.
Monday the 24th sees the swell fade to 1.4m with a light cross-onshore wind. It’s small and weak.
Tuesday the 25th is another blowout. A 2.3m SW swell gets chopped to pieces by a fresh cross-onshore E wind at 25-30 km/h. The forecast is blunt: poor surf conditions.
Wednesday the 26th returns to cleaner conditions. A more manageable 1.8m swell with a clean cross-offshore wind. Energy drops to 1044, but it’s still good for experienced surfers.
Thursday the 27th is similar, with a smaller 1.2m to 1.3m swell and clean offshore winds. Low on energy, but clean.
Friday the 28th is when it kicks off again. The morning has a long-period 17-second swell at 2.1m with a clean cross-offshore wind. Energy is massive at 4394! That long period could make it break a bit straight, but it’ll be powerful. The afternoon is a full-on 3.5m beast with 5501 energy. That’s a hard no from me.
Saturday the 29th and Sunday the 30th are both blown out. Strong onshore winds with solid 2.4m to 3.0m swells make for terrible, lumpy conditions.
But then, Monday the 31st brings another standout window. A clean 2.5m
Short Range ForecastMostly dry. Very mild (max 16°C on Tue afternoon, min 10°C on Thu night). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 2mm), mostly falling on Sat morning. Very mild (max 18°C on Fri afternoon, min 10°C on Fri morning). Winds decreasing (strong winds from the NW on Sat morning, calm by Sun morning). | ||||||||||||||||||||
Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | |||||||||||||||
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 12 | SW 13 | SW 12 | SW 12 | SW 12 | SW 12 | SW 13 | SW 12 | SW 12 | SW 11 | SSW 11 | WSW 11 | WSW 10 | SW 13 | SW 13 | SW 12 | SW 11 | SW 11 | WSW 12 | WSW 11 | SW 13 |
Wave Graph | |||||||||||||||||||||
1768 | 2458 | 2148 | 1665 | 1451 | 1878 | 3078 | 2218 | 1249 | 882 | 394 | 311 | 1420 | 5432 | 4418 | 2244 | 1642 | 1172 | 497 | 370 | 1240 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | cross-on | cross | cross-off | cross-off | on | on | cross-on | cross-on | cross-on | off | off | cross-off | off | glassy | cross-on | glassy | glassy | 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 | 12:28PM0.39m | 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 | ||||||||
7:20 | — | — | 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 | — | — | — | — | — | — | — | — | — | — | — | — | 1 | 1 | — | — | — | — | — | — | — |
Temp °C | 15 | 16 | 13 | 14 | 15 | 13 | 15 | 15 | 12 | 15 | 18 | 13 | 14 | 16 | 14 | 13 | 15 | 12 | 14 | 15 | 12 |
Feels °C | 14 | 14 | 9 | 13 | 13 | 11 | 14 | 13 | 9 | 13 | 16 | 13 | 7 | 9 | 12 | 12 | 13 | 11 | 13 | 14 | 11 |
Swell 1 Height (m) Direction Period (s) | SW 12 | SW 13 | SW 12 | SW 12 | SW 12 | SW 12 | SW 13 | SW 12 | SW 12 | SW 11 | SSW 11 | WSW 11 | — | SW 13 | SW 13 | SW 12 | SW 11 | SW 11 | WSW 12 | SSW 10 | SW 13 |
1768 | 2458 | 2148 | 1665 | 1451 | 1878 | 3078 | 2218 | 1249 | 882 | 394 | 311 | — | 5432 | 4418 | 2244 | 1642 | 1172 | 497 | 320 | 1240 | |
Swell 2 Height (m) Direction Period (s) | SW 12 | E 11 | E 10 | E 10 | E 10 | — | — | — | — | SSW 11 | WSW 11 | SSW 11 | — | — | — | SSW 11 | — | SSW 10 | SSW 10 | WSW 11 | SW 16 |
882 | 9 | 2 | 2 | 2 | — | — | — | — | 387 | 379 | 265 | — | — | — | 716 | — | 502 | 325 | 370 | 326 | |
Swell 3 Height (m) Direction Period (s) | E 11 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SSW 14 | W 11 |
9 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 127 | 62 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | E 3 | ENE 3 | — | WNW 4 | WSW 10 | — | — | — | — | — | — | — | — |
— | — | — | — | — | — | — | — | 2 | 3 | — | 21 | 1420 | — | — | — | — | — | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 25 | 32 | 10 | 0 | 0 | 0 | 30 | 32 | 10 | 4 | 23 | 8 | 60 | 25 | 10 | 0 | 4 | 10 | 4 | 32 |
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.











