
Surf Forecasts:
Ammonias surf forecast from 4 Sep 2026:
- Best quality surf: Wednesday 9 Sep, 2AM (local time) - 5ft (1.5m), 10s period, ENE swell with glassy winds.
- Most powerful swell: Monday 7 Sep, 11PM (local time) - 18ft (5.5m), 13s period, SSW swell with 11,213 kJ wave energy.
- Next surfable swell (1★+): Wednesday 9 Sep, 2AM (local time) - 5ft (1.5m), 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 2AM. The primary swell is predicted to be 1.5m and 10s period with a secondary swell of 1.1m and 8s. 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 13s 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 2.2m 11s period and expected on Tuesday (Sep 08) at 8AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Wed 9th Sep) | 5ft (1.5m) 10s |
| Best Surf | 2AM (Wed 9th Sep) | 5ft (1.5m) 10s |
| Most Powerful | 11PM (Mon 7th Sep) | 18ft (5.5m) 13s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let's take a look at what's cooking at Ammonias over the next couple of weeks.
We’ve got a mixed bag on the way. The early part of the outlook looks pretty average, with a bit of size but the wind is a real issue. The best bet for a decent wave looks like it might be Saturday the 5th. You've got a solid 7ft of ENE groundswell pumping through, with a 14-second period, so there's some proper energy behind it. The wave energy is strong too, sitting at 2854 (moderate to strong). The wind is a cross-shore breeze at 16 mph, which will put a bit of a texture on it, so it won't be glassy, but it's manageable. It's a reef break and it's fairly consistent, but be warned, crowds are often around. The water temp is a balmy 81°, which is about what you'd expect for this time of year.
Now, things go a bit sideways after that. Sunday the 6th and Monday the 7th get a lot of size, but the wind turns ugly. We're talking 10ft to 15ft of SW groundswell with a very long 15-second period and wave energy hitting over 11967 (very strong). That sounds epic, right? Wrong. The wind is howling onshore and lumpy, making it a complete mess. That kind of setup looks far more interesting for kite surfing than paddle surfing. The combined energy is huge, but the quality is zero for us.
The middle of the week sees the swell drop right back. From around Tuesday the 9th, we're looking at tiny 3ft waves with a long-period groundswell from the SSW. The water will be clean enough at times, but there just isn't enough size to get excited about. It’s a blank run for a solid week.
There is a late flicker of hope around Wednesday the 16th of September. We get a return of 3ft SSW groundswell with an 18-second period and the wind is a clean cross-shore. The energy is moderate (1096). It's still small, but the long period and clean conditions mean the set waves will have more push. For a point break or reef like Ammonias, those long-period swells can wrap in nicely. It's a long-range call, so keep an eye on it, but for now, Saturday the 5th is your standout. Get out there for the best of what's on offer.
Rusty.
Short Range ForecastHeavy rain (total 24mm), heaviest during Sun night. Warm (max 26°C on Fri morning, min 24°C on Fri night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 32mm), heaviest during Mon night. Warm (max 28°C on Tue afternoon, min 25°C on Mon morning). Winds decreasing (strong winds from the SE on Mon night, calm by Tue night). | ||||||||||||||||||||
Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | |||||||||||||||
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) | SSE 12 | SSE 12 | S 11 | ENE 14 | ENE 13 | ENE 13 | ENE 13 | SSW 14 | SSW 14 | SSW 15 | SW 15 | SSW 12 | S 9 | ENE 11 | ENE 10 | SSW 14 | SSW 13 | ENE 8 | ENE 7 | ENE 7 | ENE 7 |
Wave Graph | |||||||||||||||||||||
766 | 680 | 596 | 1859 | 1512 | 1654 | 1544 | 1941 | 2673 | 4230 | 9882 | 6367 | 846 | 757 | 436 | 341 | 257 | 178 | 261 | 273 | 188 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross | cross | cross-on | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross | cross | glassy | cross-on | cross-on | cross-on | cross | cross | cross |
High Tide | 10:57AM0.61m | 12:04PM0.65m | 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 | ||||||||
Low Tide | 3:24AM0.06m | 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 | ||||||||||
6:20 | — | — | 6:20 | — | — | 6:20 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | |
— | 6:51 | — | — | 6:50 | — | — | 6:49 | — | — | 6:47 | — | — | 6:46 | — | — | 6:45 | — | — | 6:45 | — | |
mm | — | 1 | — | — | — | 2 | 2 | 2 | 17 | 5 | 5 | 18 | 2 | — | — | — | 1 | 1 | 1 | — | — |
Temp °C | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 25 | 26 | 26 | 27 | 28 | 26 | 27 | 27 | 26 | 26 | 26 | 25 |
Feels °C | 24 | 24 | 23 | 25 | 24 | 25 | 25 | 25 | 25 | 24 | 25 | 22 | 28 | 29 | 30 | 30 | 30 | 28 | 25 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | SSE 12 | SSE 12 | S 11 | S 12 | S 13 | S 12 | SSW 13 | SSW 14 | SSW 14 | SSW 15 | SW 15 | ENE 12 | S 9 | ENE 11 | ENE 10 | ENE 9 | ENE 8 | SSW 13 | SSW 13 | E 12 | E 12 |
766 | 680 | 596 | 874 | 1145 | 1098 | 1256 | 1941 | 2673 | 4230 | 9882 | 1108 | 846 | 757 | 436 | 221 | 147 | 178 | 173 | 108 | 153 | |
Swell 2 Height (m) Direction Period (s) | E 14 | E 14 | E 14 | SSW 18 | SSW 18 | SE 10 | SSE 10 | SSE 10 | SSW 17 | SSE 9 | E 13 | SSW 15 | ENE 11 | SSW 8 | S 8 | SSW 14 | SSW 13 | E 13 | E 12 | SSW 12 | SSW 16 |
196 | 289 | 485 | 121 | 64 | 23 | 38 | 38 | 376 | 344 | 623 | 566 | 814 | 402 | 153 | 341 | 257 | 166 | 110 | 123 | 175 | |
Swell 3 Height (m) Direction Period (s) | S 21 | WSW 13 | SSW 19 | NNE 10 | NNE 10 | SSE 10 | SSE 10 | N 10 | SSE 10 | NW 14 | NNW 13 | NW 12 | W 10 | SSW 14 | SSW 14 | S 8 | E 13 | S 7 | SW 17 | SW 18 | SSW 12 |
9 | 16 | 37 | 20 | 18 | 36 | 38 | 8 | 38 | 8 | 17 | 6 | 524 | 449 | 356 | 74 | 173 | 27 | 137 | 154 | 83 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 14 | ENE 13 | ENE 13 | ENE 13 | ENE 12 | ENE 7 | ENE 12 | SE 8 | SSW 12 | — | — | — | — | — | ENE 8 | ENE 7 | ENE 7 | ENE 7 |
390 | 330 | 297 | 1859 | 1512 | 1654 | 1544 | 1360 | 545 | 1559 | 1462 | 6367 | — | — | — | — | — | 163 | 261 | 273 | 188 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 31 | 33 | 31 | 16 | 31 | 16 | 33 | 126 | 33 | 126 | 296 | 33 | 32 | 32 | 0 | 16 | 31 | 31 | 16 | 31 | 16 |
Best forecast wave conditions in Kaua'i | |||||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
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










