Surf Forecasts:
Ammonias surf forecast from 29 Aug 2026:
- Most powerful swell: Tuesday 1 Sep, 11PM (local time) - 7ft (2.2m), 8s period, ENE swell with 597 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 2.2m 8s and forecast to arrive on Tuesday (Sep 01) at 11PM. Winds are predicted to be cross-shore at the time the swell arrives.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 11PM (Tue 1st Sep) | 7ft (2.2m) 8s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright, folks, Rusty here. Let’s not sugarcoat the start of this forecast—it’s a dud. From the 28th of August through the 10th of September, we’re looking at a wall of onshore and cross-shore wind, short-period windswell, and a generally chopped-up ocean. The swell energy is up and down, mostly in that moderate range, but the period is stuck under 10 seconds and the wind is just never giving us a clean surface. All that combo means poor conditions, and it’s a long gap with nothing worth the drive.
The one shining light in this whole 16-day stretch is Friday, September 11th. That morning, the wind shifts to a light offshore, and the swell direction swings to the SSE, which is the ideal direction for this reef. You’ve got a 5ft swell with a 10-second period (call it 1.6m), but the energy reading jumps to a strong 1145, which is real power. It’s set to be excellent for experienced surfers—not too big, but with that proper groundswell push.
Then Friday afternoon is the real treat. The wind goes glassy, absolutely calm. Swell drops a touch to 5ft (1.5m), still from the SSE, and the energy is at 924. This is one of those clean, lined-up reef sessions where it all comes together. That’s your standout. The water is sitting at 81°F (27°C), which is about normal for this time of year.
There’s a brief pulse of bigger swell—around 7ft (2.1m–2.2m)—on the 8th and 9th from the ENE, but with that 8-second period and cross wind, it’s going to be a bumpy, lumpy mess. I’d leave that for the kite crew.
The good window slams shut on the 12th as the wind goes cross-on and the swell loses its juice. So, mark your calendar for the 11th. That morning, and especially that glassy afternoon, is your window. It’s a long way out, so don’t book your flights yet, but it’s the only real chance for a memorable wave.
Rusty.
Short Range ForecastLight rain (total 9mm), mostly falling on Sat morning. Warm (max 27°C on Fri afternoon, min 25°C on Fri night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 9mm), mostly falling on Mon night. Warm (max 27°C on Mon afternoon, min 24°C on Tue night). Wind will be generally light. | |||||||||||||||||||
Fri 28 | Saturday 29 | Sunday 30 | Monday 31 | Tuesday 1 | Wednesday 2 | Thursday 3 | ||||||||||||||
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) | S 14 | S 14 | S 13 | S 13 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | S 16 | S 16 | ENE 8 | ENE 8 | ENE 8 | ENE 8 |
Wave Graph  | ||||||||||||||||||||
 kJ | 394 | 294 | 215 | 215 | 336 | 443 | 334 | 345 | 390 | 362 | 494 | 421 | 499 | 547 | 435 | 406 | 494 | 398 | 314 | 243 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | cross-on | cross | cross-on | cross-on | cross | cross-on | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross |
High Tide | 4:02PM0.59m | 4:22AM0.42m | 4:25PM0.55m | 5:07AM0.46m | 4:47PM0.49m | 5:58AM0.49m | 5:08PM0.42m | 6:57AM0.52m | 5:24PM0.35m | 8:09AM0.55m | 5:17PM0.30m | 9:35AM0.57m | ||||||||
Low Tide | 10:29PM0.08m | 10:02AM0.10m | 10:52PM0.06m | 10:51AM0.15m | 11:17PM0.04m | 11:48AM0.20m | 11:45PM0.03m | 1:02PM0.26m | 00:18AM0.03m | 3:05PM0.29m | 1:01AM0.04m | 2:01AM0.05m | ||||||||
 |  |  | |  | | | | | | | | | |  | | |  | |  | |
 | — | — | 6:18 | — | — | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — |
 | 6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:54 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — |
mm | — | — | 1 | — | 4 | — | — | 2 | 2 | — | 1 | — | — | 4 | 2 | 2 | — | — | — | — |
Temp °C | 27 | 25 | 26 | 26 | 25 | 26 | 27 | 25 | 26 | 27 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 26 | 24 | 25 | 24 | 24 | 24 | 25 | 24 | 25 | 26 | 24 | 25 | 25 | 24 | 26 | 26 | 25 | 26 | 26 | 24 |
Swell 1 Height (m) Direction Period (s) | S 14 | S 14 | S 13 | S 13 | S 12 | S 12 | S 12 | SSW 15 | SSW 15 | SSW 14 | SSW 19 | S 18 | S 18 | S 17 | S 16 | S 16 | S 15 | S 14 | S 14 | S 13 |
| kJ | 394 | 294 | 215 | 215 | 141 | 100 | 100 | 196 | 191 | 180 | 391 | 314 | 314 | 373 | 427 | 406 | 352 | 268 | 243 | 176 |
Swell 2 Height (m) Direction Period (s) | E 15 | E 14 | E 13 | E 13 | SSW 17 | SSW 16 | SSW 16 | S 11 | S 11 | S 11 | S 10 | S 9 | S 12 | SSE 10 | SSE 10 | S 10 | S 11 | S 10 | E 13 | E 12 |
| kJ | 72 | 107 | 89 | 125 | 186 | 171 | 162 | 90 | 82 | 81 | 74 | 45 | 103 | 34 | 33 | 55 | 86 | 75 | 82 | 73 |
Swell 3 Height (m) Direction Period (s) | SSW 19 | SW 19 | SW 18 | SSW 17 | E 12 | W 11 | ENE 11 | ENE 11 | S 21 | SE 8 | SSW 15 | SSW 14 | SW 14 | SW 14 | SSW 12 | SSW 13 | E 15 | E 13 | S 10 | SSE 11 |
| kJ | 35 | 90 | 80 | 115 | 75 | 9 | 42 | 40 | 35 | 32 | 21 | 75 | 53 | 49 | 26 | 17 | 38 | 85 | 50 | 37 |
Wind waves Height (m) Direction Period (s) | ENE 6 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 |
| kJ | 125 | 182 | 182 | 207 | 336 | 443 | 334 | 345 | 390 | 362 | 494 | 421 | 499 | 547 | 435 | 373 | 494 | 398 | 314 | 243 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 31 | 16 | 31 | 122 | 31 | 38 | 299 | 16 | 31 | 16 | 16 | 16 | 31 | 16 | 31 | 16 | 16 | 16 | 31 | 16 |
Best forecast wave conditions in Kaua'i | ||||||||||||||||||||
Best forecast wave conditions in United States | ||||||||||||||||||||
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)
FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Ammonias 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 Ammonias Surf forecast
The above surf forecast table for Ammonias provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Ammonias can be found by selecting the local surf guide option on the grey menu. Our Ammonias 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 (Ammonias) 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 Ammonias 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 vacation in Kaua'i? If you are looking for accommodation near Ammonias, camping, hotels and condos and appartments in Kaua'i, consider staying in Nawiliwili which is 2 km (1 miles) away. Alternatively, find information about places to stay and car hire in Lihue - Kauai which is 3 km (2 miles) away
Nearest