Surf Forecasts:
Trespassers surf forecast from 17 Aug 2026:
- Best quality surf: Friday 21 Aug, 3AM (local time) - 5ft (1.5m), 15s period, SW swell with glassy winds.
- Most powerful swell: Friday 21 Aug, 12PM (local time) - 5.5ft (1.7m), 17s period, SW swell with 1,697 kJ wave energy.
- Next surfable swell (1★+): Monday 17 Aug, 6PM (local time) - 4ft (1.2m), 15s period with SW swell.
Best Forecast Surf Conditions for Trespassers this week:
The surf forecast for Trespassers over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Monday (Aug 17) at 6PM. The primary swell is predicted to be 1.2m and 15s period with a secondary swell of 0.4m and 21s. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Trespassers in the next 16 days are 1.7m 17s and forecast to arrive on Friday (Aug 21) at 12PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 4s period and expected on Monday (Aug 17) at 9PM.
| Wave Type | Time (ACST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 6PM (Mon 17th Aug) | 4ft (1.2m) 15s |
| Best Surf | 3AM (Fri 21st Aug) | 5ft (1.5m) 15s |
| Most Powerful | 12PM (Fri 21st Aug) | 5.5ft (1.7m) 17s |
Table - best surf conditions forecast for Trespassers over the next 16 days.
The Lowdown
Alright, let’s get into it. The main story here is all about one spot, Trespassers. It’s not pumping every day, but there are a couple of windows that look genuinely special for those who can handle a big, clean reef wave.
We kick off Monday the 17th with some modest, long-period southwest groundswell, but it’s not quite happening – marginal at best, with a moderate cross-off breeze. The 4ft to 4ft swell (16 seconds) has energy, but it’s just not coming together with the conditions, so we’re in a waiting game.
Tuesday the 18th is much the same story: clean-looking surf on paper, with that long 16 to 17-second period, but the wave quality just isn’t delivering. The swell is a bit small and the wind is a bit too strong from the north-northeast. A frustrating start.
Wednesday the 19th is a write-off. The wind swings onshore, the swell is junky and short-period – don’t even bother. The same goes for Thursday the 20th; there’s a lot of energy in the water but the cross-onshore wind is making a mess of things.
Now, we start to see a shift. Friday the 21st of August, the swell bumps up to a solid 5ft to 5ft, with that lovely 15 to 17-second period. The wind is light and cross-onshore, so it’s not perfect, but it’s getting there. Conditions are still marginal, but you can feel a change coming.
Here’s the standout. Saturday the 22nd. The morning is where it’s at. The swell holds a clean 5ft from the southwest, period still a beautiful 15 seconds, and the wind goes glassy. Absolutely glassy. The water will be smooth as a mirror for a bit. This is the one to circle. It’s a fairly consistent reef, but it is an advanced wave, so take your A-game.
Sunday the 23rd sees light onshore winds creep back in, and the swell drops a touch. Still surfable, but not the same quality as Saturday morning. We then hit a flat, poor stretch from Monday 24th through Wednesday 26th – the swell drops right away, and it’s just ordinary.
Then things get interesting again. Thursday the 27th of August, the swell is back up, 6ft to 7ft, with a massive 17-second period and enormous energy. The wind is cross-off, but the size and power make it a marginal call for most. This is big.
The other true standout. Friday the 28th of August. This is for experts only. The swell is showing 8ft to 10ft from the southwest. The morning has glassy conditions with a period of 10 seconds, and by the afternoon it’s completely calm and glassy with a 10ft swell. This will be a heavy, powerful, and very serious wave at Trespassers. Not for the faint-hearted, but if you have the skills, it will be epic.
Saturday the 29th drops back to a manageable 5ft to 6ft with clean conditions, a good option for the less extreme. Sunday the 30th is smaller again but still clean and fun. Monday the 31st sees a push of 7ft swell, but it’s a bit wind-affected. The window closes out after that with onshore winds and dropping energy on the 1st of September.
So, to sum it up: The clear highlights are the morning of Saturday the 22nd for a clean, glassy, medium-sized SW groundswell, and the day of Friday the 28th of August for the big, expert-only, glassy, massive SW groundswell. Trespassers is a reef, so that long-period swell will really line up nicely there.
Rusty.
Short Range ForecastLight rain (total 2mm), mostly falling on Tue night. Very mild (max 16°C on Tue afternoon, min 12°C on Mon morning). Winds decreasing (fresh winds from the NNE on Tue night, light winds from the WNW by Wed night). | Days 4-6 Weather SummaryMostly dry. Very mild (max 16°C on Sat night, min 13°C on Thu morning). Wind will be generally light. | ||||||||||||||||||||
Monday 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | |||||||||||||||
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 16 | SW 16 | SW 15 | SW 17 | SSW 16 | SW 16 | SW 15 | WSW 9 | SW 13 | SW 16 | SW 16 | SW 15 | SW 15 | SW 17 | SW 16 | SW 15 | SW 16 | SSW 15 | SSW 14 | SW 16 | SSW 15 |
Wave Graph | |||||||||||||||||||||
587 | 729 | 489 | 687 | 458 | 255 | 236 | 368 | 755 | 967 | 793 | 1046 | 953 | 1471 | 1431 | 1103 | 1193 | 987 | 672 | 1031 | 592 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-off | cross-off | cross-on | on | on | on | cross-on | on | glassy | cross-on | cross-on | cross-on | glassy | on | on | on | cross-on | on |
High Tide | 4:06PM0.02m | 6:39AM0.01m | 3:55PM0.02m | 7:35AM0.01m | 3:32PM0.02m | 2:53PM0.02m | 2:19PM0.02m | 2:13PM0.02m | 2:21PM0.02m | ||||||||||||
Low Tide | 10:39AM0.01m | 11:20PM-0.00m | 11:01AM0.01m | 11:29PM-0.00m | 11:06AM0.01m | 11:48PM-0.00m | 00:04AM0.00m | 00:16AM0.00m | 00:18AM0.00m | 11:45PM0.00m | |||||||||||
7:01 | — | — | 7:00 | — | — | 6:58 | — | — | 6:58 | — | — | 6:56 | — | — | 6:54 | — | — | 6:54 | — | — | |
— | 5:51 | — | — | 5:52 | — | — | 5:52 | — | — | 5:52 | — | — | 5:53 | — | — | 5:54 | — | — | 5:55 | — | |
mm | — | — | — | — | — | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 1 |
Temp °C | 13 | 14 | 12 | 14 | 16 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 15 | 15 | 16 | 14 | 14 | 14 |
Feels °C | 9 | 10 | 6 | 9 | 11 | 8 | 8 | 8 | 10 | 11 | 11 | 13 | 12 | 11 | 12 | 13 | 12 | 14 | 11 | 10 | 11 |
Swell 1 Height (m) Direction Period (s) | SW 16 | SW 16 | SW 15 | SW 17 | SSW 16 | SW 16 | SW 15 | SW 15 | SW 13 | SW 16 | SW 16 | SW 15 | SW 15 | SW 17 | SW 16 | SW 15 | SW 16 | SSW 15 | SSW 14 | SW 16 | SSW 15 |
587 | 729 | 489 | 687 | 458 | 255 | 236 | 255 | 755 | 967 | 793 | 1046 | 953 | 1471 | 1431 | 1103 | 1193 | 987 | 672 | 1031 | 592 | |
Swell 2 Height (m) Direction Period (s) | SW 24 | SW 22 | SSW 19 | SSW 18 | SSW 16 | ENE 4 | — | SW 20 | SSW 18 | SSW 16 | SW 14 | SW 20 | SW 18 | — | — | SW 24 | SSW 22 | SSW 20 | SSW 18 | — | SW 21 |
22 | 119 | 248 | 106 | 105 | 2 | — | 64 | 221 | 164 | 158 | 136 | 460 | — | — | 22 | 91 | 253 | 486 | — | 18 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | SW 18 | — | — | — | — | — | — | — | — | — | — | — | — |
— | — | — | — | — | — | — | — | 260 | — | — | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | ESE 3 | E 4 | ENE 4 | NE 4 | N 3 | NNW 4 | W 6 | WSW 9 | — | — | — | — | — | — | — | — | — | — | — | — | — |
4 | 4 | 16 | 5 | 8 | 32 | 146 | 368 | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 18 | 2 | 112 | 18 | 100 | 162 | 165 | 731 | 14 | 17 | 17 | 0 | 13 | 17 | 13 | 0 | 13 | 14 | 14 | 13 | 138 |
Best forecast wave conditions in Yorke Peninsula | |||||||||||||||||||||
Best forecast wave conditions in Australia | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
Information about the Trespassers Surf forecast
The above surf forecast table for Trespassers provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Trespassers can be found by selecting the local surf guide option on the grey menu. Our Trespassers 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 (Trespassers) 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 Trespassers 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 Yorke Peninsula? If you are looking for accommodation near Trespassers, camping, hotels and holiday cottages in Yorke Peninsula, consider staying in Kingscote which is 86 km (53 miles) away.











