Surf Forecasts:
Ammonias surf forecast from 23 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.
| 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
G'day, Rusty here. Let's have a look at what's on the cards for Ammonias.
Alright, straight up – the next couple of weeks are a bit of a mixed bag. We're dealing with a lot of cross-shore and cross-onshore winds, which means a lot of choppy, lumpy conditions. The wave energy is moderate for most of it, with combined energy values usually in the 500–900 range, but the quality just isn't there for most of the run. There's a long gap of poor to marginal surf from now until early September, so don't bother rushing out.
Looking at the first week, from Sunday the 23rd through to the end of August, every session is a write-off. The wind is a constant 15–16 mph from the NE or ENE, blowing cross or cross-on, and the swell is a short-period 7-second ENE windswell around 5–6 ft. It's just messy, with poor surf conditions. The water temperature anomaly is about average for this time of year, so nothing weird there.
Early September shows a little more promise. On Tuesday the 1st of September, we get a bit of a bump. The swell from the ENE picks up to 6 ft with a period of 9–10 seconds, and the combined energy jumps to 1258 – that's strong energy. The wind is a gentler 9 mph from the NE, still cross-shore, but it's only a slight cross-chop. It's still marginal, but it's the best we've seen in a while. Wednesday the 2nd brings a cleaner, longer-period S swell at 3 ft with a 16-second period, but it's cross-onshore and energy drops a bit to 993–1029. Still, that long period groundswell could shape up okay if the wind plays nice.
Then we hit a rough patch again from Thursday the 3rd through to Saturday the 5th – more ENE windswell around 5–6 ft with 8-second period, and winds picking up to 19 mph. It's just lumpy and poor.
Now, the standout window is early on Sunday the 6th of September. The morning looks glassy – I mean proper glassy – with a light 3 mph SSE breeze. The swell is a small 2 ft SSW groundswell with a very long 19-second period, and combined energy is 742. That's a moderate energy, but with glassy conditions, that long-period groundswell will wrap in cleanly. It's a reef break, so that long period will stack up nicely. This is the best on offer by a long shot, but it's over a week away, so fingers crossed it holds together. The wind goes to crap in the afternoon, so get out early.
The final day, Monday the 7th, is back to a 6 ft ENE windswell with onshore wind, so nothing to get excited about.
So, if you're keen, pencil in that Sunday morning session on the 6th of September. The rest of the forecast is a lot of waiting.
Rusty.
Short Range ForecastLight rain (total 3mm), mostly falling on Mon morning. Warm (max 27°C on Sun afternoon, min 25°C on Sat night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 2mm), mostly falling on Fri morning. Warm (max 26°C on Wed morning, min 24°C on Wed night). Wind will be generally light. | ||||||||||||||||||
Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | ||||||||||||||
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 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | E 7 | SSW 14 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 |
Wave Graph | |||||||||||||||||||
362 | 301 | 254 | 299 | 268 | 268 | 232 | 268 | 341 | 247 | 276 | 395 | 573 | 699 | 553 | 465 | 334 | 320 | 294 | |
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 | cross-on | cross | cross | cross | cross | cross | cross-on | cross | cross-on |
High Tide | 00:35AM0.22m | 1:46PM0.62m | 1:16AM0.25m | 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 | ||||||
Low Tide | 9:13PM0.18m | 5:45AM0.08m | 9:16PM0.18m | 6:37AM0.05m | 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 | ||||||
— | 6:16 | — | — | 6:16 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | |
7:01 | — | 7:01 | — | — | 7:00 | — | — | 7:00 | — | — | 6:59 | — | — | 6:58 | — | — | 6:57 | — | |
mm | — | — | — | — | 2 | 1 | — | — | — | — | — | — | — | — | — | — | 2 | — | 1 |
Temp °C | 25 | 26 | 27 | 25 | 26 | 27 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 26 | 26 | 27 | 25 | 27 | 28 | 26 | 26 | 26 | 25 | 25 | 25 | 24 | 26 | 26 | 25 | 25 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | SSW 16 | SSW 15 | SSW 15 | SSW 14 | SSW 14 | SE 9 | SE 8 | SE 8 | SSW 16 | SSE 9 | SSW 14 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 |
212 | 196 | 188 | 183 | 163 | 101 | 64 | 59 | 193 | 50 | 276 | 395 | 573 | 699 | 553 | 465 | 334 | 320 | 294 | |
Swell 2 Height (m) Direction Period (s) | WNW 11 | S 13 | SE 10 | SE 12 | SE 10 | SSW 13 | SSW 12 | SSW 16 | SSW 12 | SSW 15 | S 18 | SSW 13 | SSW 13 | SSW 12 | S 12 | SSW 11 | SSW 11 | E 15 | E 14 |
98 | 130 | 69 | 47 | 61 | 156 | 121 | 201 | 85 | 167 | 167 | 133 | 135 | 79 | 73 | 39 | 40 | 67 | 91 | |
Swell 3 Height (m) Direction Period (s) | S 14 | SE 9 | SSE 13 | SSE 13 | S 12 | SSW 18 | SSW 16 | SSW 12 | SSE 13 | SSW 12 | SSE 12 | W 10 | SE 8 | W 9 | NNE 8 | NNE 8 | E 16 | SSW 19 | SSW 10 |
107 | 27 | 59 | 58 | 77 | 61 | 153 | 83 | 33 | 79 | 14 | 8 | 16 | 7 | 13 | 19 | 43 | 35 | 18 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | E 7 | E 7 | E 7 | ENE 6 | ENE 6 | E 6 | E 6 | ENE 6 | ENE 6 | ENE 7 |
362 | 301 | 254 | 299 | 268 | 268 | 232 | 268 | 341 | 247 | 226 | 202 | 134 | 139 | 108 | 89 | 147 | 165 | 268 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 31 | 33 | 31 | 31 | 16 | 16 | 31 | 16 | 16 | 33 | 16 | 16 | 16 | 16 | 16 | 31 | 16 | 38 |
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











