Surf Forecasts:
Ammonias surf forecast from 28 Aug 2026:
- Most powerful swell: Friday 4 Sep, 11AM (local time) - 6ft (1.8m), 12s period, ENE swell with 872 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 1.8m 12s and forecast to arrive on Friday (Sep 04) at 11AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.2m 10s period and expected on Wednesday (Sep 02) at 8AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 11AM (Fri 4th Sep) | 6ft (1.8m) 12s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright mate, Rusty here.
First up, let’s be straight with you. The next 16 days are looking pretty average for Ammonias. We’ve got a run of mediocre conditions, so don’t go planning a day off work just yet. The water temp is sitting at about 81°F—pretty much spot on for this time of year, so you won’t need a steamer.
The combo energy is all over the shop, from weak to moderate most of the time, with a few bursts of strong energy later in the run. But that’s the thing—strong energy doesn’t mean good surf if the wind is rubbish.
For the first week, from Friday 28 August right through to the end of the month, it’s a no-go. The swell is coming from the south, around 3ft to 3ft at best, but the wind is a moderate cross-shore or cross-onshore breeze from the ENE at 16 mph. That’s going to leave a chop on the surface. The energy is weak-to-moderate, around 566 to 656 on the scale. Not worth paddling out for.
Sunday 30 August and Monday 31 August show a bump in swell to 6ft to 6ft, but it’s short period wind swell at 7 to 8 seconds, and the wind stays messy. It’s a cross-shore chop, so nothing clean. The energy creeps up into the moderate range, around 622 to 718, but it’s not the kind of day you’d get excited about.
Tuesday 1 September sees the swell hit 7ft to 7ft, and the energy jumps into the 1000s—strong energy now. But again, the period is short at 8 seconds, and the wind is a cross-shore from the NE or ENE. The conditions are described as marginal, with a cross-chop. For a reef break like Ammonias, that’s a bit of a washout. You’d want cleaner conditions for this spot.
Wednesday 2 September brings a cleaner line of swell from the south, with a long period of 16 seconds. The swell height drops to 3ft, but the energy is still moderate at 858. The problem is the wind goes cross-onshore from the ENE, putting a chop on what could be a nice groundswell. It’s a bit of a tease.
Thursday 3 September and Friday 4 September show a mix. Friday morning has a 6ft swell from the ENE with a 12-second period, which is a bit more organised, and the energy jumps to 1115. The wind is cross-shore, so it’s not perfect, but it’s the best of a bad bunch. Still, the conditions are only described as marginal, so keep expectations low.
The second week, from Saturday 5 September onwards, is a mixed bag of lumpy, choppy, and messy. The swell gets bigger—up to 10ft on Tuesday 8 September with a very strong energy of 2239 to 2305—but the wind is a fresh breeze from the NE at 19 mph, and the period is short at 9 seconds. That’s going to be a big, bumpy, unruly mess. For a reef break, that’s not ideal. It might be more interesting for the kite surfers than paddle surfers.
The standout, if you can call it that, is Friday 4 September morning. The swell is 6ft from the ENE, period 12 seconds, and the energy is 1115. The wind is cross-shore from the ENE at 16 mph. It’s not glassy, but it’s the best of the run. The direction is ENE, which is not the absolute optimum for Ammonias (optimum is SSE), but it’s something.
After that, it’s a blank run with no real recommendations. The surf stays poor through to Saturday 12 September, with the swell dropping to 2ft by the end.
So, honestly, I’d say give it a miss for the next 16 days unless you’re desperate. The forecast can always change, but right now, it’s not looking like a surfer’s paradise.
Rusty.
Short Range ForecastLight rain (total 8mm), mostly falling on Sat morning. Warm (max 27°C on Fri afternoon, min 25°C on Fri night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 22mm), heaviest during Wed night. Warm (max 27°C on Mon afternoon, min 24°C on Mon night). Wind will be generally light. | ||||||||||||||||||||
Friday 28 | Saturday 29 | Sunday 30 | Monday 31 | Tuesday 1 | Wednesday 2 | Thursday 3 | |||||||||||||||
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) | S 14 | S 14 | S 14 | S 13 | S 13 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | S 16 | S 16 | ENE 8 | ENE 8 | ENE 8 | S 13 |
Wave Graph | |||||||||||||||||||||
334 | 394 | 294 | 215 | 215 | 346 | 376 | 358 | 356 | 363 | 400 | 475 | 604 | 583 | 465 | 427 | 406 | 520 | 361 | 306 | 285 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross-on | cross | cross-on | cross-on | cross | cross-on | cross-on | cross | cross | cross | cross | cross | cross-on | cross | cross-on | cross | cross | cross |
High Tide | 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 | 8:09AM0.55m | 5:17PM0.30m | 9:35AM0.57m | |||||||||
Low Tide | 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 | 3:05PM0.29m | 1:01AM0.04m | 2:01AM0.05m | ||||||||
6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | |
— | 6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:54 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | |
mm | — | — | — | 1 | — | 4 | 1 | — | 2 | — | 1 | 1 | 1 | 2 | 7 | — | 1 | 9 | — | — | 2 |
Temp °C | 26 | 27 | 25 | 26 | 26 | 25 | 26 | 27 | 26 | 26 | 27 | 25 | 26 | 26 | 25 | 27 | 27 | 25 | 26 | 26 | 25 |
Feels °C | 25 | 26 | 24 | 25 | 24 | 24 | 25 | 25 | 25 | 25 | 27 | 24 | 25 | 25 | 25 | 27 | 27 | 24 | 24 | 25 | 25 |
Swell 1 Height (m) Direction Period (s) | S 14 | S 14 | S 14 | S 13 | S 13 | S 12 | S 12 | S 12 | SSW 15 | SSW 15 | SSW 14 | SSW 19 | S 18 | S 18 | S 17 | S 16 | S 16 | S 15 | S 14 | S 14 | S 13 |
334 | 394 | 294 | 215 | 215 | 141 | 100 | 100 | 196 | 144 | 180 | 391 | 314 | 314 | 373 | 427 | 406 | 352 | 268 | 243 | 285 | |
Swell 2 Height (m) Direction Period (s) | SSW 11 | E 15 | E 14 | E 13 | E 13 | SSW 17 | SSW 16 | SSW 16 | S 11 | S 11 | S 11 | S 10 | SSW 14 | S 12 | SSE 10 | SSE 10 | S 11 | S 11 | S 10 | E 13 | E 12 |
40 | 72 | 107 | 89 | 125 | 186 | 171 | 162 | 89 | 82 | 79 | 51 | 76 | 105 | 35 | 33 | 62 | 61 | 52 | 84 | 107 | |
Swell 3 Height (m) Direction Period (s) | E 16 | SSW 19 | SW 19 | SW 18 | SSW 17 | E 12 | E 12 | ENE 11 | ENE 11 | ENE 10 | SE 8 | SE 8 | S 9 | SW 14 | SW 14 | SSW 13 | SSW 13 | E 15 | E 13 | S 10 | SW 18 |
45 | 35 | 90 | 80 | 115 | 75 | 71 | 42 | 40 | 33 | 32 | 9 | 43 | 53 | 52 | 17 | 17 | 38 | 55 | 31 | 12 | |
Wind waves Height (m) Direction Period (s) | ENE 6 | ENE 6 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 7 |
160 | 125 | 182 | 182 | 201 | 346 | 376 | 358 | 356 | 363 | 400 | 475 | 604 | 583 | 465 | 381 | 372 | 520 | 361 | 306 | 254 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 31 | 16 | 16 | 31 | 46 | 38 | 38 | 126 | 16 | 31 | 16 | 16 | 31 | 31 | 16 | 31 | 31 | 33 | 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











