
Surf Forecasts:
Ammonias surf forecast from 6 Aug 2026:
- Most powerful swell: Wednesday 12 Aug, 2PM (local time) - 4ft (1.2m), 18s period, S swell with 891 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 1.2m 18s and forecast to arrive on Wednesday (Aug 12) 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 (Wed 12th Aug) | 4ft (1.2m) 18s |
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 coming our way.
First off, I’ve gotta be straight with you—this outlook is a tough one. We’re looking at a 16-day window, and truth is, the first week is pretty much a write-off for any decent surf. There’s a big gap from the start all the way through to the second week before we see anything that gets the heart pumping. The wind is a persistent problem, mostly cross or cross-onshore from the ENE, and the swell is all over the place in size and direction but never really lining up right.
The best stretch of the whole period looks like it’ll be around Wednesday 12th August through to Friday 14th August. That’s when we finally get a pulse of proper swell from the south, with some long period energy. On Wednesday afternoon, you’ll see a 4ft south swell with a period of 18 seconds, and the combined energy is strong at 1310. That’s the kind of groundswell that gets your attention. The catch? The wind is cross-shore from the ENE, so it’s not going to be glassy, but it’s rideable. The water temp is sitting around 80°F, which is bang on average for this time of year, so no surprises there.
The standout break here is Ammonias, a reef setup that’s fairly consistent. That long period south swell will wrap in nicely here, given the reef handles that kind of energy better than a beach break. The crowd factor is "often", so expect company, but for the quality on offer, it’s worth it. The swell direction from the south is a good match for the break’s optimum swell from SSE. Just keep in mind, with a period over 15 seconds, the sets will be clean and powerful, but there will be longer lulls between them.
By the time we get into the second week, the south swell fades and we’re back to shorter period ENE windswell, with the wind staying onshore or cross. The swell sizes build up to 8ft, but with periods of only 7-8 seconds and that constant ENE breeze, it’s going to be lumpy and messy. Honestly, for the last few days of the window, the setup at Ammonias looks more interesting for kite surfing than paddle surfing, given the strong wind and choppy conditions.
So, to wrap it up: the first week is a dud. Your best bet is to target that mid-week window from Wednesday 12th August through Friday 14th August, when the south groundswell hits. It’s not perfect, but it’s the only real stand-out in an otherwise flat or wind-affected run.
Rusty.
Short Range ForecastLight rain (total 2mm), mostly falling on Fri night. Warm (max 26°C on Wed afternoon, min 24°C on Wed night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 3mm), mostly falling on Sun afternoon. Warm (max 26°C on Sat afternoon, min 24°C on Sat night). Wind will be generally light. | |||||||||||||||||||
Wed 5 | Thursday 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | ||||||||||||||
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 10 | ENE 9 | ENE 8 | ENE 6 | ENE 8 | SW 21 | SW 20 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | SSW 16 | SSW 15 | SSW 15 | SSW 15 | SSW 14 | S 20 |
Wave Graph | ||||||||||||||||||||
166 | 90 | 197 | 119 | 159 | 125 | 98 | 148 | 182 | 219 | 285 | 319 | 328 | 355 | 259 | 234 | 231 | 222 | 207 | 485 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross-on | cross | cross | cross-on | cross | cross | cross-on | cross | cross | cross-on | cross | cross-on | cross | cross | cross | cross-on | cross | cross |
High Tide | 11:24AM0.57m | 12:26PM0.64m | 1:18PM0.69m | 00:17AM0.19m | 2:05PM0.73m | 1:24AM0.22m | 2:47PM0.75m | 2:17AM0.26m | 3:26PM0.74m | 3:06AM0.30m | ||||||||||
Low Tide | 2:46AM0.02m | 3:47AM0.01m | 4:56AM-0.01m | 9:20PM0.16m | 6:02AM-0.03m | 9:35PM0.15m | 7:01AM-0.05m | 9:56PM0.13m | 7:54AM-0.06m | 10:20PM0.12m | ||||||||||
— | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:13 | — | — | 6:13 | — | — | |
7:15 | — | — | 7:14 | — | — | 7:13 | — | — | 7:13 | — | — | 7:12 | — | — | 7:10 | — | — | 7:10 | — | |
mm | — | — | — | — | — | — | — | 1 | 1 | — | — | — | 1 | — | 1 | 1 | — | — | — | — |
Temp °C | 26 | 25 | 26 | 26 | 25 | 25 | 26 | 25 | 26 | 26 | 25 | 25 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 27 | 26 | 27 | 27 | 26 | 26 | 27 | 26 | 26 | 25 | 25 | 25 | 27 | 26 | 27 | 27 | 26 | 27 | 27 | 26 |
Swell 1 Height (m) Direction Period (s) | ENE 10 | ENE 9 | SSW 14 | SSW 14 | SSW 14 | SSE 7 | SSW 14 | SSW 14 | SSW 14 | SSW 13 | SSW 13 | SSW 13 | S 18 | SSW 16 | SSW 16 | SSW 15 | SSW 15 | SSW 15 | SSW 14 | SSW 13 |
166 | 90 | 81 | 80 | 81 | 21 | 74 | 110 | 113 | 102 | 137 | 98 | 156 | 263 | 259 | 234 | 231 | 222 | 207 | 299 | |
Swell 2 Height (m) Direction Period (s) | SSW 15 | SSW 15 | SSE 11 | SSE 11 | SE 7 | SSW 14 | SW 20 | SSW 19 | SSW 18 | SSW 18 | SW 17 | SSW 16 | SSW 12 | SSE 10 | SSE 10 | SSE 8 | SE 9 | SSE 9 | SSE 9 | S 20 |
87 | 87 | 43 | 42 | 14 | 78 | 98 | 148 | 127 | 123 | 148 | 104 | 83 | 37 | 60 | 45 | 79 | 54 | 54 | 485 | |
Swell 3 Height (m) Direction Period (s) | SSW 11 | S 12 | SSW 10 | SE 8 | S 11 | SW 21 | SE 7 | SE 7 | SE 8 | SE 8 | SE 8 | SSW 18 | SSW 16 | SSW 12 | SSW 12 | SSW 11 | SSW 11 | S 11 | SSW 11 | SSE 9 |
38 | 46 | 19 | 9 | 39 | 115 | 12 | 13 | 16 | 17 | 21 | 102 | 100 | 56 | 81 | 24 | 41 | 62 | 40 | 52 | |
Wind waves Height (m) Direction Period (s) | ENE 5 | ENE 5 | ENE 8 | ENE 6 | ENE 8 | ENE 7 | ENE 5 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 6 |
39 | 62 | 197 | 119 | 159 | 125 | 66 | 95 | 182 | 219 | 285 | 319 | 328 | 355 | 222 | 167 | 168 | 135 | 147 | 119 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 16 | 15 | 31 | 16 | 16 | 31 | 31 | 16 | 31 | 16 | 16 | 31 | 16 | 16 | 31 | 16 | 16 | 31 | 31 | 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











