Surf Forecasts:
Ammonias surf forecast from 29 Aug 2026:
- Most powerful swell: Saturday 5 Sep, 2PM (local time) - 8ft (2.4m), 8s period, ENE swell with 679 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 2.4m 8s and forecast to arrive on Saturday (Sep 05) at 2PM. 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 | 2PM (Sat 5th Sep) | 8ft (2.4m) 8s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright, Rusty here. Let's chew the fat on the next 16 days at Ammonias.
Right off the bat, I gotta be straight with you – it’s a rough stretch ahead. We’ve got a long dry spell on our hands. The first real chance of something half-decent doesn’t pop up until we get into the second week, and even then, we’re scratching for it. The water temp is sitting right around average for this time of year, nothing unusual there.
The opening weekend, starting Saturday the 29th of August, is a write-off. We’ve got small, weak swell mixed with a strong cross-onshore breeze. It’s choppy, messy, and the combined energy is weak (566). The whole first week is basically a bust – constant cross-shore wind with a cross-chop, and the swell is mostly a weak, short-period windswell that just isn't worth paddling out for. Sunday the 30th through to the following Saturday (5th of September) is all the same story: poor surf and moderate breezes ruining any shape.
We finally see a pulse of energy mid-week, but honestly, it’s not clean. Around Monday the 7th of September, the combined energy jumps up to a strong level (1207), and it peaks hard on Wednesday the 9th with a very strong reading of 2057 and solid 10ft swell. But here’s the kicker – the wind is a persistent cross-shore, which means lumpy, bumpy conditions. This is powerful, chunky surf that’s going to be a real handful. At 10ft, this is expert-only territory. The swell direction is from the ENE, but the optimum for this reef is from the SSE, so it’s not wrapping in as clean as it could. Honestly, with that much cross-shore wind and messy power, this setup probably looks more interesting for kite surfing than paddle surfing.
The one true standout, the only one worth circling on the calendar, is Friday the 11th of September. We’ve got a long-period groundswell (11 seconds) arriving from the SSE, which is bang on the optimum direction for this break. The combined wave energy is massive at 3066. Swell height hits 8ft, and the wind shifts to a cross-onshore from the ESE – not glassy, but manageable. Because it’s a long-period SSE swell hitting a reef known to like that direction, the shape should be there. Just be aware, the long period can throw big, unpredictable sets, so keep your wits about you. And with that rating of "often" for crowds, expect company out there.
Overall, the second week is a waiting game for that Friday. The rest is a lot of big, blown-out lumps or small, weak dribble. Stay patient.
- Rusty
Short Range ForecastLight rain (total 9mm), mostly falling on Sat night. Warm (max 27°C on Sun afternoon, min 24°C on Mon night). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 14mm), heaviest on Wed night. Warm (max 26°C on Tue morning, min 24°C on Tue night). Wind will be generally light. | ||||||||||||||||||||
Saturday 29 | Sunday 30 | Monday 31 | Tuesday 1 | Wednesday 2 | Thursday 3 | Friday 4 | |||||||||||||||
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) | S 13 | S 13 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | S 16 | S 16 | ENE 8 | ENE 7 | ENE 8 | S 13 | ENE 7 | ENE 7 | ENE 7 |
Wave Graph | |||||||||||||||||||||
215 | 215 | 405 | 376 | 297 | 281 | 456 | 379 | 451 | 421 | 373 | 568 | 427 | 406 | 411 | 387 | 331 | 285 | 256 | 316 | 475 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross | cross | cross-on | cross | cross | cross-on | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross | cross | cross | cross | cross |
High Tide | 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 | 10:57AM0.61m | ||||||||||
Low Tide | 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 | 3:24AM0.06m | |||||||||
6:18 | — | — | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | |
— | 6:55 | — | — | 6:54 | — | — | 6:54 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | — | 6:51 | — | |
mm | — | — | 3 | — | — | 3 | 1 | 1 | 1 | — | 1 | 2 | 2 | 2 | 5 | 2 | — | — | 1 | — | 1 |
Temp °C | 26 | 26 | 25 | 26 | 27 | 26 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 25 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 25 | 25 | 24 | 25 | 26 | 25 | 25 | 25 | 24 | 25 | 25 | 24 | 26 | 26 | 24 | 24 | 25 | 24 | 24 | 25 | 23 |
Swell 1 Height (m) Direction Period (s) | S 13 | S 13 | S 12 | S 12 | S 12 | SSW 15 | SSW 15 | S 11 | SSW 19 | S 18 | S 18 | S 17 | S 16 | S 16 | S 15 | S 14 | S 14 | S 13 | S 13 | S 13 | S 13 |
215 | 215 | 141 | 100 | 100 | 196 | 191 | 82 | 391 | 314 | 314 | 373 | 427 | 406 | 352 | 268 | 243 | 285 | 222 | 165 | 162 | |
Swell 2 Height (m) Direction Period (s) | E 13 | E 13 | SSW 17 | SSW 16 | SSW 16 | S 11 | S 11 | SSW 14 | S 10 | SSW 14 | S 12 | SSE 10 | S 10 | SSE 10 | S 11 | S 10 | E 13 | E 12 | E 13 | E 13 | E 12 |
89 | 125 | 186 | 171 | 162 | 89 | 82 | 180 | 74 | 115 | 105 | 34 | 53 | 31 | 86 | 75 | 84 | 45 | 123 | 121 | 109 | |
Swell 3 Height (m) Direction Period (s) | SW 18 | SSW 17 | E 12 | E 12 | ENE 11 | ENE 11 | S 21 | SSW 19 | SW 14 | S 9 | SW 14 | SW 14 | SSW 13 | S 12 | E 14 | E 13 | S 10 | E 14 | SE 13 | SE 11 | SE 12 |
80 | 115 | 75 | 71 | 42 | 40 | 35 | 124 | 52 | 45 | 53 | 52 | 17 | 25 | 64 | 85 | 50 | 37 | 41 | 33 | 25 | |
Wind waves Height (m) Direction Period (s) | ENE 6 | ENE 6 | ENE 7 | 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 7 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 |
188 | 207 | 405 | 376 | 297 | 281 | 456 | 379 | 451 | 421 | 373 | 568 | 402 | 300 | 411 | 387 | 331 | 247 | 256 | 316 | 475 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 31 | 16 | 16 | 33 | 33 | 16 | 31 | 16 | 16 | 16 | 31 | 16 | 16 | 16 | 16 | 16 | 31 | 16 | 31 | 31 | 31 |
Best forecast wave conditions in Kaua'i | |||||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||||
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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











