Surf Forecasts:
Ammonias surf forecast from 27 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 1.8m 8s period and expected on Monday (Aug 31) at 11PM.
| 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, let’s get into it. For this stretch, it’s looking like a bit of a grind at Ammonias. We’ve got a classic trade wind setup pushing in from the ENE, and honestly, for the next several days, it’s going to be a battle against the cross-shore and cross-onshore wind. The first real window we can look at is Thursday morning the 27th. We’ve got a decent swell rolling in—call it 4ft from the south with a long 17-second period. That’s proper groundswell energy, with the combined energy reading moderate at 949. The problem? That ENE wind at 15 mph is making a mess of things. It’s cross-shore and the surface is going to be chopped up. You’ll see it, but it won’t be clean. The afternoon cleans up slightly to clear skies, but that wind stays on it. The swell drops a touch to 3ft, and the period backs off a bit, but it’s still a struggle. Honestly, it’s not worth getting too excited about.
Friday the 28th is more of the same. We’re looking at 3ft of south swell with a 14-second period, and that ENE cross-shore wind is still hanging around at 15 mph. The morning is questionable, the afternoon just turns into poor conditions. The energy is dropping too. It’s a holding pattern.
Then things get interesting in a bad way. Saturday the 29th into Sunday the 30th, the swell direction swings around to the ENE, and it jumps up in size to 6ft, then 6ft. But the period crashes down to 6-7 seconds. That’s pure wind swell, short and crumbly, and with that same ENE wind pushing onshore, it’s going to be a choppy, bumpy mess. The combined energy stays moderate, but the quality is zero. You might get some bigger waves, but they won’t be rideable in any meaningful way. This is more of a nuisance than anything else.
We’re looking at a gap of a few days here where there’s nothing worth paddling out for. From Saturday through to Wednesday the 2nd, it’s all that wind-blown ENE swell, with the size ranging from 5ft to 7ft, but all of it with short, weak periods. There are a couple of moments where a longer period south swell tries to sneak in, like Wednesday afternoon the 2nd, when we get a 3ft south swell with a 16-second period, but the wind is still cross-shore and it’s messy. It’s just not coming together.
The beginning of September is a dead zone. From Thursday the 3rd through to Saturday the 5th, the swell drops off, the periods are short, and the wind is still cross-shore or cross-on. It’s flat and poor. There’s nothing to get excited about. This is a real lull.
Now, looking further out, there’s a glimmer of hope. Sunday the 6th of September brings a bit more energy. The combined swell energy jumps up to strong at 1124, and we’ve got a mix of swells—4ft from the ENE with an 11-second period, and a 3ft from the SSW with a 16-second period. The wind drops to a light breeze, but it’s still cross-onshore. It’s a marginal call, but it’s the most surfable it’s looked in a while. Then Monday the 7th looks a touch better for size, with 4ft of SSW groundswell at 16 seconds, and the energy still strong at 1113. The wind is light, but still cross-onshore. It’s promising, but it’s a ways off, so don’t book your flights yet.
The second week is more of the same—small, inconsistent south swells with ENE winds messing things up. There’s a moment on Wednesday the 9th in the afternoon where the wind swings to a cross-offshore from the NNE and conditions look clean with 3ft of SSW swell at 13 seconds. That’s a window, but it’s a small one. And then we hit Thursday and Friday the 10th and 11th, where we’re back to ENE wind swell, cross-on, and risk of thunderstorms. It’s not looking great.
All in all, this is a pretty bleak run for Ammonias. The reef there can handle a bit of swell, but it’s just not getting any clean waves for a while. There’s a lot of energy moving around, but the wind is just not our friend. You might get one or two windows if you’re desperate and local, but for the most part, it’s a waiting game. The long period south swells are there, but they’re being buried under the wind chop. Keep the board in the car, but maybe don’t rush to the water just yet.
Rusty
Short Range ForecastLight rain (total 2mm), mostly falling on Fri night. Warm (max 27°C on Fri afternoon, min 24°C on Fri night). Wind will be generally light. | Days 5-7 Weather SummaryModerate rain (total 13mm), heaviest on Tue afternoon. Warm (max 27°C on Sun afternoon, min 24°C on Mon night). Wind will be generally light. | ||||||||||||||||||
Thursday 27 | Friday 28 | Saturday 29 | Sunday 30 | Monday 31 | Tuesday 1 | ||||||||||||||
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 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 | S 13 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | SSW 19 | ENE 9 | ENE 9 | S 17 |
Wave Graph | |||||||||||||||||||
573 | 699 | 553 | 567 | 334 | 320 | 294 | 233 | 215 | 326 | 321 | 263 | 233 | 339 | 302 | 295 | 489 | 454 | 400 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross-on | cross-on | cross | cross | cross | cross | cross | cross | cross | cross-on |
High Tide | 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 | 6:57AM0.52m | 5:24PM0.35m | |||||||
Low Tide | 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 | 1:02PM0.26m | 00:18AM0.03m | ||||||
— | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — | |
6:59 | — | 6:58 | — | — | 6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:54 | — | — | 6:53 | — | |
mm | — | — | — | — | — | — | 2 | — | — | — | 1 | — | 2 | 2 | — | 3 | 2 | 3 | 10 |
Temp °C | 26 | 26 | 26 | 25 | 26 | 27 | 25 | 26 | 27 | 26 | 26 | 27 | 26 | 26 | 27 | 25 | 26 | 27 | 26 |
Feels °C | 25 | 25 | 25 | 25 | 25 | 27 | 24 | 25 | 26 | 25 | 25 | 26 | 26 | 26 | 26 | 25 | 26 | 28 | 27 |
Swell 1 Height (m) Direction Period (s) | 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 | SSW 15 | S 11 | SSW 19 | SSW 18 | S 18 | S 17 |
573 | 699 | 553 | 567 | 334 | 320 | 294 | 219 | 215 | 141 | 100 | 100 | 196 | 191 | 110 | 295 | 333 | 314 | 368 | |
Swell 2 Height (m) Direction Period (s) | SSW 13 | SSW 12 | S 12 | W 10 | SSW 11 | E 15 | E 14 | E 13 | E 13 | SSW 17 | SSW 16 | SSW 16 | S 11 | S 11 | SSW 14 | S 10 | S 10 | S 12 | S 10 |
135 | 79 | 73 | 8 | 39 | 72 | 107 | 89 | 125 | 186 | 171 | 162 | 89 | 82 | 180 | 51 | 65 | 110 | 74 | |
Swell 3 Height (m) Direction Period (s) | W 10 | NNE 8 | NNE 8 | E 18 | E 16 | SSW 19 | SW 19 | SW 18 | SSW 17 | E 12 | E 12 | ENE 11 | ENE 11 | E 10 | SSW 19 | SSW 14 | SSW 14 | SW 14 | SW 14 |
7 | 7 | 6 | 24 | 45 | 35 | 90 | 80 | 115 | 75 | 71 | 42 | 39 | 31 | 124 | 79 | 108 | 53 | 52 | |
Wind waves Height (m) Direction Period (s) | E 6 | E 7 | E 6 | E 6 | ENE 6 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | NE 8 | ENE 9 | ENE 9 | ENE 8 |
200 | 171 | 139 | 171 | 176 | 129 | 212 | 233 | 212 | 326 | 321 | 263 | 233 | 339 | 302 | 428 | 489 | 454 | 400 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 16 | 16 | 16 | 16 | 31 | 16 | 33 | 33 | 38 | 33 | 31 | 16 | 31 | 31 | 14 | 16 | 16 | 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











