
Surf Forecasts:
Ammonias surf forecast from 8 Sep 2026:
- Best quality surf: Tuesday 8 Sep, 2AM (local time) - 31ft (9.5m), 14s period, SSW swell with cross-onshore winds.
- Most powerful swell: Tuesday 8 Sep, 2AM (local time) - 31ft (9.5m), 14s period, SSW swell with 33,043 kJ wave energy.
- Next surfable swell (1★+): Tuesday 8 Sep, 2AM (local time) - 31ft (9.5m), 14s period with SSW swell.
Best Forecast Surf Conditions for Ammonias this week:
The surf forecast for Ammonias over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Sep 08) at 2AM. The primary swell is predicted to be 9.5m and 14s period with a secondary swell of 2.3m and 10s. The wind is predicted to be cross-onshore as the swell arrives.
The most powerful waves expected at Ammonias in the next 16 days are 9.5m 14s and forecast to arrive on Tuesday (Sep 08) at 2AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 8s period and expected on Sunday (Sep 13) at 8PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Tue 8th Sep) | 31ft (9.5m) 14s |
| Best Surf | 2AM (Tue 8th Sep) | 31ft (9.5m) 14s |
| Most Powerful | 2AM (Tue 8th Sep) | 31ft (9.5m) 14s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
G’day, it’s Rusty here. Let’s be straight with you: the next couple of weeks at Ammonias are looking pretty average, maybe even a bit of a write-off for most of it. We’ve got a run of poor conditions and inconsistent energy, so you’ll need patience if you’re keen for a paddle.
The first real window worth getting excited about doesn’t even show up until Thursday the 17th. That’s over a week away. Before that, we’re looking at a lot of smaller, junky surf. The first few days have some size, with an 12ft SSW swell on Tuesday morning, but the wind is howling cross-shore at 22 mph and it’ll be lumpy, messy chaos. Not worth the fight.
The wind eases a touch through Wednesday and Thursday, but the swell drops right off, and we’re stuck with weak, short-period leftovers. The energy numbers are down in the low hundreds, and the waves are mostly under 3ft. It’s choppy and cross-onshore, with plenty of “poor” comments in there. Friday the 11th and the weekend are much the same – small, weak, and messy. You’d be better off finding something else to do.
The real bright spot lands on Thursday afternoon, September 17th. Finally, the stars align. The wind goes glassy, and we get a clean 3ft SSW groundswell with a long 16-second period. The energy is still only moderate at 801, but the description says “expect very good surf conditions,” and that’s the standout of the whole run. It’s not big, but it’ll be clean and lined up. The period is long, so it might get a bit straight on the reef, but it’s your best chance for a proper wave.
The Friday and Saturday after that still have that SSW groundswell pulse, with 4ft on Friday afternoon and 3ft on Saturday, periods around 16-17 seconds. Winds stay light, though mostly cross-onshore, which isn’t perfect, but it’s still better than everything before it.
After that, it fades back into the small, choppy mush. The energy dips low again, and the models suggest we’re back to waiting.
So there you have it. The 17th is the one to circle. Get out there Thursday arvo if you can; it’s clean and glassy. The rest is a grind. It’s a poor stretch, but these runs don’t usually last forever.
Rusty.
Short Range ForecastHeavy rain (total 35mm), heaviest during Mon night. Warm (max 27°C on Tue morning, min 25°C on Wed night). Winds decreasing (severe gales from the SSE on Mon night, calm by Wed night). | Days 5-7 Weather SummarySome drizzle, heaviest during Thu night. Warm (max 26°C on Fri morning, min 24°C on Thu night). Wind will be generally light. | ||||||||||||||||||
Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | ||||||||||||||
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) | SSW 14 | SSW 9 | ENE 11 | ENE 11 | SSW 14 | SSW 13 | SSW 13 | ENE 8 | ENE 7 | ENE 7 | SW 16 | ENE 11 | ENE 11 | ENE 10 | ENE 10 | SSW 13 | SSW 15 | ENE 9 | SSW 14 |
Wave Graph | |||||||||||||||||||
33043 | 1848 | 737 | 531 | 336 | 253 | 178 | 244 | 314 | 254 | 198 | 387 | 436 | 163 | 125 | 98 | 84 | 108 | 79 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross | cross | cross | cross-on | on | cross | cross-on | cross-on | cross | cross-on | cross | cross-on | cross-on | cross-on | cross | cross-on | cross-on | cross |
High Tide | 1:36AM0.30m | 2:20PM0.68m | 2:21AM0.36m | 2:54PM0.66m | 3:04AM0.41m | 3:24PM0.61m | 3:47AM0.47m | 3:51PM0.55m | 4:29AM0.51m | 4:16PM0.48m | 5:11AM0.54m | 4:38PM0.41m | |||||||
Low Tide | 8:46PM0.13m | 7:02AM0.02m | 9:05PM0.11m | 7:55AM0.03m | 9:25PM0.09m | 8:43AM0.05m | 9:45PM0.07m | 9:31AM0.09m | 10:06PM0.05m | 10:19AM0.13m | 10:28PM0.04m | 11:10AM0.18m | 10:50PM0.04m | ||||||
— | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | |
6:47 | — | 6:46 | — | — | 6:45 | — | — | 6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:42 | — | |
mm | 31 | 2 | — | — | — | — | — | — | 2 | 1 | — | — | — | — | — | — | — | — | — |
Temp °C | 26 | 27 | 27 | 26 | 27 | 27 | 26 | 27 | 26 | 25 | 26 | 26 | 25 | 26 | 25 | 25 | 26 | 26 | 25 |
Feels °C | 18 | 26 | 27 | 28 | 30 | 29 | 30 | 29 | 27 | 26 | 26 | 26 | 26 | 27 | 26 | 26 | 27 | 27 | 26 |
Swell 1 Height (m) Direction Period (s) | ENE 10 | ENE 12 | ENE 11 | ENE 11 | ENE 10 | ENE 9 | ENE 8 | SSW 13 | SSW 12 | SW 16 | SW 16 | SW 15 | SW 15 | ENE 10 | ENE 10 | NE 9 | NE 8 | NE 8 | NE 8 |
1020 | 814 | 693 | 531 | 264 | 165 | 103 | 173 | 172 | 211 | 198 | 229 | 226 | 163 | 125 | 81 | 74 | 72 | 57 | |
Swell 2 Height (m) Direction Period (s) | NNW 12 | SSW 15 | SSW 14 | SSW 8 | SSW 14 | SSW 13 | SSW 13 | E 12 | E 12 | SSW 12 | E 11 | NNE 8 | SSW 11 | NE 8 | NE 9 | ENE 9 | ENE 9 | SW 15 | SSW 14 |
14 | 494 | 449 | 223 | 336 | 253 | 178 | 108 | 104 | 81 | 91 | 32 | 23 | 70 | 79 | 48 | 46 | 54 | 79 | |
Swell 3 Height (m) Direction Period (s) | — | SW 20 | NW 8 | SSW 14 | S 8 | S 7 | E 13 | SSW 17 | SW 18 | E 12 | S 12 | SSW 12 | SE 8 | SW 16 | SSW 16 | SSW 13 | SSW 15 | SE 9 | ENE 8 |
— | 15 | 43 | 431 | 90 | 54 | 119 | 186 | 154 | 99 | 71 | 46 | 18 | 124 | 99 | 98 | 84 | 20 | 28 | |
Wind waves Height (m) Direction Period (s) | SSW 14 | SSW 9 | SSW 8 | — | — | — | — | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 11 | ENE 11 | — | — | E 5 | ENE 6 | ENE 9 | ENE 5 |
33043 | 1848 | 737 | — | — | — | — | 244 | 314 | 254 | 162 | 387 | 436 | — | — | 55 | 31 | 108 | 31 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 320 | 34 | 23 | 11 | 11 | 33 | 10 | 14 | 31 | 16 | 31 | 31 | 15 | 31 | 12 | 15 | 14 | 12 | 14 |
Best forecast wave conditions in Kaua'i | |||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||
Header Global | |||||||||||||||||||
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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










