
Surf Forecasts:
Ammonias surf forecast from 6 Sep 2026:
- Best quality surf: Wednesday 9 Sep, 5AM (local time) - 4.5ft (1.3m), 10s period, ENE swell with glassy winds.
- Most powerful swell: Monday 7 Sep, 11PM (local time) - 18ft (5.5m), 15s period, SSW swell with 13,249 kJ wave energy.
- Next surfable swell (1★+): Wednesday 9 Sep, 5AM (local time) - 4.5ft (1.3m), 10s period with ENE swell.
Best Forecast Surf Conditions for Ammonias this week:
The surf forecast for Ammonias over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Wednesday (Sep 09) at 5AM. The primary swell is predicted to be 0.9m and 14s period with a secondary swell of 1.3m and 10s. Another secondary swell of 1.1m and 8s is also forecast. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Ammonias in the next 16 days are 5.5m 15s and forecast to arrive on Monday (Sep 07) at 11PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.7m 10s period and expected on Tuesday (Sep 08) at 2PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5AM (Wed 9th Sep) | 4.5ft (1.3m) 10s |
| Best Surf | 5AM (Wed 9th Sep) | 4.5ft (1.3m) 10s |
| Most Powerful | 11PM (Mon 7th Sep) | 18ft (5.5m) 15s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let's have a look at what's on the table for Ammonias over the next couple of weeks.
Right off the bat, I gotta be straight with you – it's a pretty grim start. We're looking at a solid week of onshore junk and messy conditions before anything remotely rideable shows up. The first real chance to paddle out comes around Tuesday the 8th of September in the afternoon. The swell drops a bit to 6ft from the ENE, but the wind swings cross-shore, making it less of a battle. The combined energy is still moderate at (1346), but it's only a marginal call. Not exactly a standout.
Honestly, the best of the bunch, and I mean the *only* real window, looks like Wednesday the 9th of September. Early morning we've got some glassy conditions with a light offshore from the SSE, and the swell, though small at 3ft from the SSW, has some decent period to it (14 seconds) – that's proper groundswell energy. The combined energy is weak at (633), but for a reef break like Ammonias, that long-period swell could wrap in nicely. It'll be clean and uncrowded, with the optimum swell direction from SSE matching up. That's your window, boys. Get it while you can because it doesn't last.
After that, it's back to onshore slop and tiny, weak waves for the rest of the fortnight. There are a few afternoon windows where the wind goes cross-shore and the swell bumps up a little to around 5ft-5ft, like Friday the 11th and Saturday the 12th, but the periods are short and choppy. They're marginal at best.
Further out, towards the 18th and 19th of September, we see a slight uptick in swell to around 4ft-4ft from the SSW with longer periods (16-18 seconds), but the wind stays cross or cross-onshore, killing any real quality. The energy climbs into the moderate range (900-989), but the conditions just won't cooperate. That's the story for the second week – a few hints of energy but no clean windows.
So, bottom line: if you're keen, make the most of Wednesday morning the 9th. It's the only clean, glassy chance we get. Otherwise, this stretch is a write-off. The rest is for the kites.
Stay salty,
Rusty
Short Range ForecastHeavy rain (total 97mm), heaviest during Mon morning. Warm (max 27°C on Tue morning, min 24°C on Sun night). Winds decreasing (near gales from the SE on Mon night, moderate winds from the SW by Tue afternoon). | Days 5-7 Weather SummaryLight rain (total 5mm), mostly falling on Wed afternoon. Warm (max 27°C on Wed morning, min 24°C on Thu night). Wind will be generally light. | ||||||||||||||||||
Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | ||||||||||||||
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 13 | ENE 13 | ENE 12 | SSW 14 | SSW 15 | SSW 15 | SW 14 | SSW 10 | ENE 11 | ENE 10 | SSW 14 | SSW 13 | SSW 13 | ENE 7 | ENE 7 | SW 16 | SSW 16 | ENE 12 | ENE 11 |
Wave Graph | |||||||||||||||||||
1654 | 1521 | 1360 | 1355 | 2813 | 5004 | 10414 | 970 | 757 | 427 | 341 | 257 | 178 | 280 | 254 | 211 | 164 | 560 | 540 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross | cross | on | on | cross-on | cross-on | cross-on | cross | cross-on | cross | cross |
High Tide | 11:37PM0.20m | 12:57PM0.68m | 00:45AM0.25m | 1:42PM0.69m | 1:36AM0.30m | 2:20PM0.68m | 2:21AM0.36m | 2:54PM0.66m | 3:04AM0.41m | 3:24PM0.61m | 3:47AM0.47m | 3:51PM0.55m | 4:29AM0.51m | ||||||
Low Tide | 8:23PM0.17m | 8:30PM0.15m | 6:02AM0.04m | 8:46PM0.13m | 7:02AM0.02m | 9:05PM0.11m | 7:55AM0.03m | 9:25PM0.09m | 8:43AM0.05m | 9:45PM0.07m | 9:31AM0.09m | 10:06PM0.05m | |||||||
— | 6:20 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | |
6:50 | — | 6:49 | — | — | 6:47 | — | — | 6:46 | — | — | 6:45 | — | — | 6:45 | — | — | 6:44 | — | |
mm | 3 | 2 | 3 | 31 | 35 | 6 | 14 | 3 | — | — | — | 3 | 1 | 1 | — | — | — | — | 1 |
Temp °C | 25 | 26 | 26 | 25 | 25 | 26 | 26 | 27 | 27 | 26 | 27 | 27 | 26 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 24 | 26 | 25 | 25 | 24 | 24 | 23 | 27 | 27 | 29 | 29 | 30 | 29 | 28 | 27 | 26 | 26 | 26 | 25 |
Swell 1 Height (m) Direction Period (s) | S 12 | SSW 12 | SSW 12 | SSW 14 | SSW 15 | SSW 15 | SW 14 | WSW 10 | SSW 8 | ENE 10 | ENE 9 | ENE 8 | ENE 7 | SSW 13 | SSW 12 | E 12 | E 12 | SSW 15 | SW 15 |
547 | 486 | 718 | 1355 | 2813 | 5004 | 10414 | 850 | 589 | 427 | 199 | 131 | 157 | 186 | 119 | 106 | 141 | 150 | 226 | |
Swell 2 Height (m) Direction Period (s) | SSW 16 | SSW 16 | SSW 19 | E 12 | SSE 9 | NNW 13 | ENE 12 | ENE 11 | ENE 11 | S 8 | SSW 14 | SSW 13 | SSW 13 | E 12 | E 12 | SW 16 | SSW 16 | SSW 12 | SE 8 |
144 | 382 | 122 | 472 | 208 | 17 | 1231 | 874 | 757 | 208 | 341 | 257 | 178 | 106 | 104 | 211 | 164 | 46 | 18 | |
Swell 3 Height (m) Direction Period (s) | SE 10 | SSE 10 | SSE 10 | SSW 18 | NW 14 | — | NNW 12 | SE 7 | W 9 | SSW 14 | S 8 | SSW 8 | E 13 | SSW 17 | SW 18 | SSW 12 | SSW 12 | SE 9 | SSW 11 |
27 | 36 | 38 | 352 | 8 | — | 14 | 176 | 276 | 356 | 93 | 58 | 115 | 186 | 154 | 82 | 79 | 20 | 22 | |
Wind waves Height (m) Direction Period (s) | ENE 13 | ENE 13 | ENE 12 | ENE 7 | ENE 7 | ESE 8 | SE 8 | SSW 10 | — | — | — | — | — | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 12 | ENE 11 |
1654 | 1521 | 1360 | 335 | 665 | 1200 | 1010 | 970 | — | — | — | — | — | 280 | 254 | 172 | 144 | 560 | 540 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 31 | 38 | 33 | 303 | 133 | 249 | 32 | 32 | 11 | 32 | 32 | 14 | 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










