Surf Forecasts:
Ammonias surf forecast from 24 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, Rusty here. Let's have a look at what's on the table for this stretch. Frankly, it’s a tough run. We’re looking at a spot called Ammonias, a reef setup that needs a solid south-southeast pulse to really fire, but the wind gods are not playing ball for the most part.
The water’s sitting at a warm 81° right now, which is pretty much bang on average for this time of year, nothing to write home about.
The first week is a real grind. From Monday the 24th all the way through to Friday the 4th of September, it’s a whole lot of average to poor conditions. The swell hangs around 2ft to 7ft, mostly from the east or east-northeast, which is the opposite of what this reef wants. The problem is the wind: it’s a persistent moderate cross or cross-onshore breeze from the ENE at 12 to 16 mph, keeping things choppy and messy. The wave energy (586 to 950) says there’s some push, but the short period of 6 to 8 seconds means weak, crumbly waves. You’d be fighting a losing battle. There’s nothing here that’d get me paddling out.
The only real glimmer in this whole outlook arrives around Thursday the 5th of September into the weekend. We get a proper shift as a long period swell shows up from the south-southwest, with periods jumping to 17 to 20 seconds. That’s the kind of groundswell that can make a reef like Ammonias talk. The swell height is small, only 2ft to 4ft, but that long period energy (759 to 1122) means clean, lined-up waves. The problem? The wind is still a moderate cross or cross-onshore ENE breeze, so it won’t be glassy perfection. But with that direction and period, the reef could offer up some nice, walling rides, especially for the more experienced crew. It’s still a cross-shore chop out there, so it’s not a standout by any means, just the least worst of a bad bunch.
To sum it up: the first 12 days are a write-off for a good surf. You’re waiting until the 5th of September for the south-southwest groundswell to show up, and even then, the wind keeps it from being a classic. For beginners, the swell is small enough, but the choppy conditions are no fun. For experts, that long period groundswell might offer a few gems if you can work around the breeze. The energy is moderate, but the quality just isn’t there.
Rusty.
Short Range ForecastLight rain (total 5mm), mostly falling on Mon morning. Warm (max 27°C on Mon morning, min 24°C on Wed night). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 6mm), mostly falling on Fri morning. Warm (max 26°C on Thu morning, min 24°C on Thu night). Wind will be generally light. | ||||||||||||||||||||
Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | Sunday 30 | |||||||||||||||
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) | ENE 7 | ENE 7 | ENE 7 | ENE 6 | E 7 | E 7 | E 7 | 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 |
Wave Graph | |||||||||||||||||||||
278 | 276 | 239 | 245 | 328 | 212 | 278 | 395 | 573 | 699 | 553 | 567 | 334 | 394 | 294 | 247 | 255 | 262 | 197 | 339 | 325 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross-on | cross-on | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross | cross | cross | cross | cross-on | cross | cross |
High Tide | 2:19PM0.63m | 1:51AM0.28m | 2:48PM0.64m | 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 | ||||||||
Low Tide | 9:23PM0.17m | 7:21AM0.04m | 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 | ||||||||
6:16 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | |
— | 7:00 | — | — | 7:00 | — | — | 6:59 | — | — | 6:58 | — | — | 6:57 | — | — | 6:55 | — | — | 6:54 | — | |
mm | 2 | 2 | — | 1 | — | — | — | — | — | — | — | — | 2 | 1 | 1 | — | — | 2 | 1 | — | — |
Temp °C | 27 | 27 | 26 | 26 | 27 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 28 | 28 | 27 | 25 | 27 | 25 | 25 | 25 | 24 | 25 | 25 | 25 | 26 | 25 | 24 | 25 | 25 | 24 | 26 | 25 | 25 |
Swell 1 Height (m) Direction Period (s) | SSW 14 | SE 9 | SE 8 | SE 8 | SSW 16 | 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 |
163 | 70 | 72 | 59 | 193 | 167 | 215 | 395 | 573 | 699 | 553 | 567 | 334 | 394 | 294 | 215 | 215 | 141 | 136 | 136 | 196 | |
Swell 2 Height (m) Direction Period (s) | SE 10 | SSW 13 | SSW 12 | SSW 16 | SSW 12 | SSE 8 | S 18 | SSW 13 | SSW 13 | SSW 12 | S 12 | NNE 7 | SSW 11 | E 15 | E 14 | E 14 | E 13 | E 13 | SSW 16 | SSW 16 | S 11 |
58 | 156 | 121 | 201 | 85 | 48 | 167 | 133 | 135 | 79 | 73 | 11 | 40 | 38 | 65 | 100 | 130 | 123 | 171 | 162 | 87 | |
Swell 3 Height (m) Direction Period (s) | SSE 12 | SSW 18 | SSW 16 | SSW 12 | SSE 13 | SSW 12 | SSE 12 | SE 8 | W 10 | N 8 | NNE 8 | W 10 | E 16 | SSW 19 | SW 19 | SW 18 | SSW 17 | SSW 17 | E 12 | E 12 | ENE 11 |
87 | 61 | 153 | 83 | 33 | 79 | 14 | 18 | 7 | 5 | 7 | 7 | 42 | 35 | 90 | 80 | 115 | 186 | 75 | 71 | 42 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 6 | E 7 | E 7 | E 7 | E 7 | E 6 | E 6 | E 6 | E 6 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 |
278 | 276 | 239 | 245 | 328 | 212 | 278 | 200 | 143 | 139 | 115 | 139 | 139 | 153 | 244 | 247 | 255 | 262 | 197 | 339 | 325 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 33 | 16 | 16 | 33 | 31 | 16 | 31 | 16 | 16 | 16 | 16 | 16 | 31 | 31 | 16 | 31 | 31 | 16 | 31 | 16 | 16 |
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











