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. The largest open ocean swell (not directed at the beach) is 0.4m 8s period and expected on Friday (Aug 28) at 2AM.
| 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
Alright folks, Rusty here with a look at what’s coming up for Ammonias over the next couple of weeks.
The first week is a bit of a slog. The swell is mostly short-period windswell in the 5 to 6 foot range, but the wind is a persistent cross-shore or cross-onshore breeze, which is keeping the surface messy. The combined energy is moderate (values between 539 and 681), but with no clean glassy window and a lumpy cross-chop, the surf just isn’t worth paddling out for. This pattern runs from the morning of Sunday, August 23rd, right through the end of the month. There are a few mornings where the swell backs off a bit, but it’s still poor.
As we move into September, things start to get interesting. On Tuesday morning, September 1st, a long-period groundswell from the S at 18 seconds pushes through at around 3 feet, and the combined energy jumps to strong (1136). The wind is still cross-shore, so it’s not perfect, but that long period means a lot more energy and shape. It’s still a marginal call, but it’s the first real sign of life.
The standout action builds from Sunday, September 6th, into Monday, September 7th. On Sunday, a solid 7-foot swell from the ENE with a 13-second period delivers very strong energy (2380 to 2424). The wind is cross-shore, but the wave quality is still marginal. The best of the lot is Monday morning, September 7th. The swell is 8 feet from the ENE with a 12-second period, and the combined energy is very strong (2699). The wind finally drops to a light breeze (15 km/h), and while it’s still cross-shore, the slight chop is a big improvement. This is the biggest, most powerful swell of the window, but at 8 feet, it’s strictly for the experts. The reef at Ammonias will be handling that energy, but with the swell direction out of the ENE and the optimum direction for this spot being SSE, it’s not a perfect match. Still, the size and power make it the one to watch if you’ve got the skills.
Between the end of August and the first week of September, there’s a gap of about four days with no real surf worth chasing. It’s a dry spell, but forecasts can always tighten up as we get closer.
Water temperature is sitting at 80°F with a negligible anomaly, so it’s pretty average for this time of year.
Rusty.
Short Range ForecastLight rain (total 8mm), mostly falling on Mon morning. Warm (max 27°C on Sun morning, min 24°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 4mm), mostly falling on Thu 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 | Saturday 29 | |||||||||||||||
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) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | E 7 | E 7 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 | E 7 | E 7 | SSW 17 |
Wave Graph | |||||||||||||||||||||
355 | 285 | 317 | 232 | 239 | 232 | 332 | 388 | 270 | 274 | 395 | 573 | 699 | 553 | 567 | 334 | 320 | 294 | 240 | 215 | 235 | |
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 | cross | cross | cross | cross | cross-on | cross | cross | cross-on | cross | cross | cross | cross | cross |
High Tide | 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 | 4:25PM0.55m | ||||||||
Low Tide | 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 | 10:02AM0.10m | 10:52PM0.06m | ||||||||
6:16 | — | — | 6:16 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | |
— | 7:01 | — | — | 7:00 | — | — | 7:00 | — | — | 6:59 | — | — | 6:58 | — | — | 6:57 | — | — | 6:55 | — | |
mm | — | — | — | 2 | 2 | 3 | 1 | — | — | — | — | — | 1 | — | 2 | — | 1 | — | — | — | 2 |
Temp °C | 27 | 27 | 26 | 27 | 27 | 26 | 26 | 27 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 27 | 27 | 26 | 28 | 28 | 28 | 26 | 27 | 25 | 24 | 24 | 24 | 26 | 26 | 26 | 26 | 25 | 24 | 26 | 25 | 25 |
Swell 1 Height (m) Direction Period (s) | SSW 15 | SSW 15 | SSW 14 | SSW 14 | SE 9 | SE 8 | SE 7 | SSW 16 | SSW 15 | SSW 14 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 | S 13 | S 13 | S 12 |
196 | 191 | 183 | 163 | 95 | 62 | 50 | 193 | 167 | 215 | 395 | 573 | 699 | 553 | 567 | 334 | 320 | 294 | 219 | 215 | 141 | |
Swell 2 Height (m) Direction Period (s) | S 13 | SE 12 | SE 12 | SE 10 | SSW 13 | SSW 12 | SSW 16 | SSW 12 | SE 9 | S 18 | SSW 13 | SSW 13 | SSW 12 | S 12 | NNE 8 | SSW 11 | E 14 | E 13 | SW 18 | E 13 | E 13 |
130 | 48 | 48 | 79 | 156 | 121 | 201 | 85 | 40 | 167 | 133 | 135 | 79 | 73 | 19 | 40 | 37 | 55 | 80 | 125 | 130 | |
Swell 3 Height (m) Direction Period (s) | WNW 10 | NW 10 | SSE 13 | SSE 14 | SSW 18 | SSW 16 | SSW 12 | SSE 13 | SSW 12 | SSE 12 | SE 8 | SE 8 | N 8 | NNE 8 | W 10 | E 15 | SSW 19 | SSW 10 | E 12 | SSW 17 | SSW 17 |
40 | 24 | 58 | 65 | 61 | 153 | 83 | 33 | 79 | 14 | 25 | 31 | 5 | 13 | 8 | 17 | 35 | 18 | 47 | 115 | 186 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | E 7 | E 7 | ENE 7 | ENE 7 | E 6 | E 6 | E 6 | ENE 7 | ENE 6 | E 6 | E 7 | E 7 | ENE 6 |
355 | 285 | 317 | 232 | 239 | 232 | 332 | 388 | 270 | 274 | 206 | 166 | 151 | 123 | 146 | 157 | 188 | 206 | 240 | 212 | 235 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 31 | 31 | 16 | 31 | 16 | 16 | 33 | 16 | 16 | 33 | 31 | 16 | 31 | 16 | 16 | 31 | 16 | 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











