Surf Forecasts:
Ammonias surf forecast from 26 Aug 2026:
- Most powerful swell: Thursday 27 Aug, 2PM (local time) - 3.5ft (1.1m), 17s period, S swell with 702 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 1.1m 17s and forecast to arrive on Thursday (Aug 27) at 2PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 7s period and expected on Friday (Aug 28) at 2AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 2PM (Thu 27th Aug) | 3.5ft (1.1m) 17s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright mate, Rusty here. Let’s have a look at what’s on the cards for Ammonias.
The outlook is a slow burner. We’ve got a long stretch of mostly marginal, cross-shore wind and pretty average conditions to sit through before things finally start looking up towards the end of the second week. There’s a solid gap of days where the surf is just not worth paddling out for, so be patient.
From Wednesday the 26th of August all the way through to the start of September, it’s a real struggle. The wind is stuck in the ENE to NE quarter, blowing moderate to fresh, and it’s mostly cross or cross-onshore. The swell is there, but it’s small, messy, and short-period. On Wednesday the 26th morning, we’ve got a 2ft SSW swell but with a 16 mph cross-onshore, so it’s choppy and poor. The water temperature is about average for the time of year, nothing out of the ordinary. The combined energy sits around 566 (moderate), but it’s not clean enough to enjoy. Afternoons and the following days are much the same—cross-shore winds, marginal wave heights around 3ft to 4ft, and the energy stays moderate (between 583 and 939). The period does drop to 7 seconds from the 30th of August, which is really short and weak. That ENE windswell stays around 5ft to 6ft, but with those short periods and cross-shore winds, it’s just a lumpy, uninviting mess. Honestly, this stretch looks more interesting for kite surfing than paddle surfing.
Then, we hit a bit of a lull again on the 2nd and 3rd of September, with the swell dropping back to 3ft from the south and cross-onshore winds. The energy is still moderate (637-760), but the quality is poor. Things don’t really improve until the 7th of September.
Now, here’s where it gets interesting. The best window of the entire forecast is Monday the 7th of September through Tuesday the 8th. Monday morning brings a 3ft SSW groundswell with a 15-second period, clean cross-off winds from the north at 16 mph, and the combined energy jumps to 1065 (strong). That’s a proper groundswell, and with the wind offshore, the reef at Ammonias will be handling it beautifully. The afternoon pushes the swell to 4ft, still clean. Then Tuesday the 8th is the real standout. Morning has a 4ft south swell, 12-second period, light north winds at 9 mph, and energy at 1104 (strong). The afternoon steps up to 5ft from the SSE, 11-second period, still clean with a light NNW breeze. The wave comment says excellent for experienced surfers, and that’s spot on. The swell direction from the SSE is right in the wheelhouse for Ammonias, and the winds are nearly glassy. It’s a reef break, so it can handle the longer period well. Keep in mind, crowds are often here, so you might have some company, but for that quality, it’s worth it.
After that, Wednesday the 9th starts to fade. Morning still has a 5ft SSE swell but the wind shifts to a light SSW cross-onshore, and the energy stays strong (1130), but it’s not as clean. The afternoon gets messy again with a 16 mph cross-shore. And by Thursday the 10th, it’s back to poor conditions with cross-onshore winds and energy dropping to 928 (moderate).
So, to wrap it up: the first week and a half is a write-off—windy, messy, and short-period junk. Hold out for Monday the 7th and Tuesday the 8th of September. Those two days at Ammonias are the real deal with clean, strong groundswell and offshore winds. That’s your window.
Rusty.
Short Range ForecastLight rain (total 4mm), mostly falling on Wed morning. Warm (max 26°C on Tue night, min 25°C on Tue night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 6mm), mostly falling on Mon morning. Warm (max 27°C on Sun afternoon, min 24°C on Fri night). Wind will be generally light. | ||||||||||||||||||
Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | Sunday 30 | Monday 31 | ||||||||||||||
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) | E 7 | SSW 14 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 |
Wave Graph | |||||||||||||||||||
176 | 215 | 395 | 573 | 699 | 553 | 567 | 334 | 394 | 289 | 219 | 215 | 295 | 293 | 285 | 256 | 307 | 264 | 508 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross |
High Tide | 2:25AM0.31m | 3:14PM0.64m | 3:02AM0.35m | 3:38PM0.62m | 3:40AM0.38m | 4:02PM0.59m | 4:22AM0.42m | 4:25PM0.55m | 5:07AM0.46m | 4:47PM0.49m | 5:58AM0.49m | 5:08PM0.42m | |||||||
Low Tide | 9:34PM0.16m | 8:01AM0.03m | 9:50PM0.13m | 8:40AM0.04m | 10:08PM0.11m | 9:19AM0.06m | 10:29PM0.08m | 10:02AM0.10m | 10:52PM0.06m | 10:51AM0.15m | 11:17PM0.04m | 11:48AM0.20m | 11:45PM0.03m | ||||||
— | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:20 | — | — | |
7:00 | — | 6:59 | — | — | 6:58 | — | — | 6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:54 | — | |
mm | — | 1 | — | — | — | — | 2 | 1 | — | 2 | 1 | — | — | — | — | 1 | 2 | — | — |
Temp °C | 26 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 25 | 26 | 25 | 26 | 27 | 25 | 26 | 27 | 25 |
Feels °C | 27 | 25 | 25 | 24 | 25 | 25 | 25 | 25 | 25 | 24 | 24 | 24 | 24 | 25 | 27 | 25 | 25 | 26 | 24 |
Swell 1 Height (m) Direction Period (s) | SSW 15 | SSW 14 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 | S 13 | S 13 | S 12 | S 12 | S 12 | SSW 15 | S 11 | S 11 | S 19 |
167 | 215 | 395 | 573 | 699 | 553 | 567 | 334 | 394 | 289 | 219 | 215 | 141 | 136 | 136 | 196 | 85 | 82 | 273 | |
Swell 2 Height (m) Direction Period (s) | SSE 9 | S 18 | SSW 13 | SSW 13 | SSW 12 | S 12 | NNE 7 | SSW 11 | E 15 | E 14 | E 13 | E 13 | SSW 17 | SSW 16 | SSW 16 | S 11 | SSW 15 | SSW 14 | S 10 |
49 | 167 | 133 | 135 | 79 | 73 | 10 | 39 | 72 | 107 | 89 | 125 | 186 | 171 | 162 | 89 | 191 | 180 | 74 | |
Swell 3 Height (m) Direction Period (s) | SSW 12 | SE 8 | SE 8 | W 10 | NNE 8 | W 10 | SE 8 | E 16 | SSW 19 | SW 19 | SW 18 | SSW 17 | E 12 | E 12 | ENE 11 | ENE 11 | E 10 | SSW 19 | SW 14 |
79 | 33 | 18 | 8 | 7 | 9 | 10 | 45 | 35 | 90 | 80 | 115 | 75 | 71 | 41 | 39 | 17 | 124 | 51 | |
Wind waves Height (m) Direction Period (s) | E 7 | E 6 | E 6 | E 6 | E 6 | ENE 6 | E 6 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 |
176 | 151 | 156 | 178 | 161 | 134 | 115 | 165 | 147 | 165 | 214 | 200 | 295 | 293 | 285 | 256 | 307 | 264 | 508 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 33 | 16 | 16 | 16 | 31 | 16 | 31 | 31 | 16 | 33 | 31 | 16 | 31 | 16 | 16 | 31 | 31 | 16 |
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











