
Surf Forecasts:
Ammonias surf forecast from 11 Sep 2026:
- Most powerful swell: Thursday 17 Sep, 8PM (local time) - 7ft (2.2m), 8s period, ENE swell with 622 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 1.0m 17s and forecast to arrive on Thursday (Sep 17) at 8PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.2m 9s period and expected on Sunday (Sep 13) at 8PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 8PM (Thu 17th Sep) | 7ft (2.2m) 8s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Right, let’s have a look at what’s cookin’ at Ammonias over the next couple weeks. It’s a reef setup that likes a bit of SSE direction for optimum, but honestly, the window's lookin’ pretty grim for most of it. The water temp is sittin’ at 80°, which is about normal for this time of year, nothing to write home about.
The first pulse we see is Thursday the 10th, but I wouldn’t paddle out. That’s a 5ft swell from the ENE with a short 7-second period, and a cross-onshore wind at 16 mph. It’s gonna be choppy junk, no two ways about it. The combined energy is moderate (710), but the conditions are just poor. That carries right through the 11th, 12th, and 13th – really weak, messy lumps of cross-onshore chop. On the 13th we get a 2ft groundswell from the SW with a 15-second period, but that energy is weak (191) and the wind keeps it bumpy.
We’ve got a real gap here. From Thursday the 10th all the way through to the 15th, it’s pretty much a write-off. Not worth the wax. The 16th and 17th show a bit more size – up to 7ft from the ENE (8-second period) – but that’s stormy with risk of thunderstorms and 16 mph cross-shore winds. The energy jumps to strong (1086), but it’s a messy, wind-blown affair. Good luck gettin’ a clean face.
Things start to look a little more promising toward the end. Wednesday the 23rd of September, late in the arvo, we’ve got a 5ft swell from the east at 12-seconds, with light cross-onshore breeze. That’s the first proper standout in the whole run – combined energy is very strong (1176) and the wind is light enough to keep it clean-ish. Still not glassy, but it’s the best on offer.
Then Thursday the 24th and Friday the 25th have a 3ft to 4ft groundswell from the SSW with a very long 18-second period, and light onshore wind. That kind of long period will wrap nicely into a reef like Ammonias, and the energy is still strong (1067 on Thursday). The wind is light and variable, so it could get clean. These are the two real highlights – the 23rd arvo and the 24th morning. They’re marginal, but compared to the rest of this forecast, they’re the ones to cherry pick.
Given the mostly poor conditions and the cross-onshore wind pattern, and the fact that Ammonias is an exposed reef, a lot of these days look more interesting for a kite surfer than a paddle surfer. The whole area feels a bit frustrating, but that little window around the 23rd to the 25th is worth a look.
Rusty.
Short Range ForecastSome drizzle, heaviest during Thu afternoon. Warm (max 27°C on Thu afternoon, min 23°C on Sat night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 7mm), mostly falling on Sun night. Warm (max 27°C on Tue afternoon, min 24°C on Sun night). Wind will be generally light. | |||||||||||||||||||
Thu 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | ||||||||||||||
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 | SW 16 | ENE 8 | ENE 11 | ENE 10 | ENE 10 | SSW 13 | SW 15 | SSW 15 | SW 14 | SW 14 | SW 22 | SW 21 | SW 20 | SW 19 | SSW 19 | SW 18 | SSW 18 | SSW 17 |
Wave Graph | ||||||||||||||||||||
280 | 225 | 198 | 226 | 404 | 209 | 169 | 98 | 104 | 84 | 99 | 49 | 227 | 224 | 392 | 384 | 465 | 449 | 541 | 355 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross | cross-on | cross | cross | cross-on | cross-on | cross | cross-on | cross | cross | cross | cross | cross | cross-on | cross | cross | cross | cross | cross |
High Tide | 3:24PM0.61m | 3:47AM0.47m | 3:51PM0.55m | 4:29AM0.51m | 4:16PM0.48m | 5:11AM0.54m | 4:38PM0.41m | 5:56AM0.55m | 4:55PM0.35m | 6:45AM0.55m | 4:58PM0.30m | 7:44AM0.54m | ||||||||
Low Tide | 9:45PM0.07m | 9:31AM0.09m | 10:06PM0.05m | 10:19AM0.13m | 10:28PM0.04m | 11:10AM0.18m | 10:50PM0.04m | 12:08PM0.22m | 11:14PM0.05m | 1:23PM0.26m | 11:40PM0.08m | 00:11AM0.10m | ||||||||
— | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:24 | — | — | 6:24 | — | — | |
6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:42 | — | — | 6:40 | — | — | 6:39 | — | — | 6:38 | — | |
mm | 1 | — | — | — | — | — | — | — | — | — | 3 | — | — | — | — | — | 2 | 2 | 1 | 3 |
Temp °C | 27 | 25 | 26 | 26 | 25 | 25 | 25 | 25 | 25 | 26 | 25 | 25 | 26 | 25 | 26 | 27 | 26 | 26 | 27 | 26 |
Feels °C | 28 | 25 | 26 | 26 | 25 | 26 | 25 | 25 | 25 | 26 | 26 | 24 | 25 | 26 | 27 | 28 | 27 | 27 | 28 | 27 |
Swell 1 Height (m) Direction Period (s) | SSW 12 | SW 16 | SW 16 | SSW 15 | SW 15 | NE 9 | NE 9 | NE 9 | NE 9 | NE 9 | NE 9 | NE 8 | SW 22 | SW 21 | NE 8 | NE 7 | SSW 19 | SW 18 | SSW 18 | SSW 17 |
172 | 211 | 198 | 150 | 226 | 75 | 84 | 115 | 115 | 115 | 93 | 120 | 227 | 224 | 125 | 105 | 465 | 449 | 541 | 355 | |
Swell 2 Height (m) Direction Period (s) | E 12 | E 12 | E 11 | SE 9 | SE 8 | SW 16 | SSW 16 | ENE 9 | SW 15 | SSW 15 | SW 14 | SW 14 | SW 14 | SW 13 | SW 20 | SW 19 | SSE 7 | E 11 | SW 11 | SSW 21 |
104 | 99 | 91 | 37 | 18 | 124 | 99 | 49 | 104 | 84 | 99 | 49 | 47 | 44 | 392 | 384 | 10 | 35 | 31 | 86 | |
Swell 3 Height (m) Direction Period (s) | SW 18 | SSW 12 | S 12 | SSW 12 | SE 6 | SSW 13 | SSW 13 | SSW 13 | SW 12 | SE 9 | ENE 9 | SE 8 | SE 8 | SE 8 | SW 12 | SSE 8 | E 11 | SW 11 | W 10 | SW 11 |
154 | 81 | 71 | 45 | 8 | 70 | 69 | 98 | 23 | 13 | 15 | 17 | 16 | 15 | 39 | 19 | 39 | 20 | 7 | 19 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 11 | ENE 10 | ENE 10 | E 4 | ENE 9 | ENE 9 | ENE 5 | ENE 5 | NE 8 | NE 8 | — | — | ENE 7 | ENE 7 | ENE 7 | ENE 7 |
280 | 225 | 162 | 226 | 404 | 209 | 169 | 19 | 64 | 62 | 56 | 24 | 153 | 142 | — | — | 142 | 198 | 281 | 355 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 31 | 16 | 31 | 31 | 16 | 31 | 12 | 16 | 31 | 31 | 16 | 31 | 31 | 16 | 31 | 31 | 16 | 31 | 16 | 31 |
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










