
Surf Forecasts:
Ammonias surf forecast from 6 Aug 2026:
- Most powerful swell: Thursday 13 Aug, 2AM (local time) - 5ft (1.5m), 16s period, S swell with 1,193 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 1.5m 16s and forecast to arrive on Thursday (Aug 13) at 2AM. Winds are predicted to be cross-onshore at the time the swell arrives.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 2AM (Thu 13th Aug) | 5ft (1.5m) 16s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let's be straight with you – the next couple of weeks are looking like a bit of a grind for your local stretch. We've got a lot of onshore energy in the water, but it's messy and not doing us any favors. The good news is, there's a window of hope in the middle, so don't write it off just yet.
Right out of the gate, for the next few days, it’s all about the ENE wind and it's not our friend. It's blowing cross-onshore and keeping things choppy. The swell is small, in the 4ft to 5ft range, with a short, weak period of 6 to 8 seconds. There’s not enough power or direction to make anything of it, and the conditions are just poor. The combined wave energy is weak to moderate, sitting around 259 to 475, but it's all for nothing with that wind.
We get a temporary bump in size on Sunday the 9th, still from the ENE with a bit more energy in the water (597), and there’s a hint of a score at 1/10 – the only one for a while – but that cross-shore wind at 16 mph is going to make it a bumpy, challenging session. It’s still not what we’d call a good option.
Then we hit a bit of a lull on Monday, with the swell dropping back down to 2ft from the SSW with a much longer 15-second period. This is a different kind of wave, but it's fighting against a cross-onshore wind and the energy is still moderate. It looks like a couple of days of small, messy surf until we get to the midweek.
Now, here's where it gets interesting. Starting Wednesday the 12th, the swell direction swings around to the south, and the energy in the water jumps up big time. We're talking a combined energy of over 1000 – that's the strong range, and it's a big upgrade from the weak junk we’ve been seeing. The swell height is 3ft to 4ft, with a solid 16 to 18-second period. The catch? The wind is still up and cross-onshore, which will wreck the surface. So, while the power is there, it’s still not going to be clean.
We carry this bigger, longer-period S swell into the 13th and 14th. On the 13th, the afternoon at least eases off from a full cross-on to a cross-shore wind, and we see our first score of 2/10 for the period. You can feel the potential. The swell is around 5ft with a 15-second period and the energy is strong (1047). It's a marginal call, but it's the best we've got. The 14th is more of the same, but the wind starts to pick up again.
The real test comes in the second week. By Saturday the 15th, the wind is still ENE and strong, blowing at 16 mph, and the swell is back to short-period ENE energy again, which is no good. The size is there – 6ft to 8ft – but it's all wind-driven and messy.
And then, for the true crew, there's the big one on Monday the 17th. We see the swell max out at 8ft from the ENE. That's a lot of water moving, but the period is only 8 seconds and the wave energy is strong (1161). However, with a fresh 19 mph cross-onshore wind, it’s going to be a beast. This is a day for the experts only, and even then, it's going to be a battle. At this size, the ENE swell and that wind are just going to create a close-out, heavy, and blown-out mess. It's more of a spectacle than a surf session. The rest of that week just fades away, dropping back to tiny SW pulses with 12 to 18-second periods, but no real energy or decent winds to make anything of it.
So, to sum it up: the standout is not a clean one, but the window on the 13th and 14th is the only time with both size and a hint of better wind, making it the pick of the fortnight. It’s about scoring a few shifty, powerful ones on the sets. The 19th and 20th see small, long-period SW swell, but it’s not going to do much. It’s a waiting game, but there’s something to keep an eye on.
Remember, forecasts can change, and sometimes a blank run like this turns around faster than you think. Keep the faith.
Rusty.
Short Range ForecastLight rain (total 2mm), mostly falling on Thu night. Warm (max 26°C on Thu morning, min 24°C on Wed night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 3mm), mostly falling on Sun morning. Warm (max 26°C on Sun afternoon, min 24°C on Sat night). Wind will be generally light. | ||||||||||||||||||
Thursday 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 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 9 | ENE 8 | ENE 6 | ENE 5 | SW 21 | SW 20 | SSW 19 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | SSW 15 | SSW 15 | SSW 15 | SSW 14 | S 20 |
Wave Graph | |||||||||||||||||||
90 | 197 | 119 | 91 | 125 | 98 | 148 | 182 | 201 | 260 | 293 | 310 | 319 | 222 | 234 | 296 | 222 | 207 | 611 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | cross | cross-on | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross-on |
High Tide | 11:24AM0.57m | 12:26PM0.64m | 1:18PM0.69m | 00:17AM0.19m | 2:05PM0.73m | 1:24AM0.22m | 2:47PM0.75m | 2:17AM0.26m | 3:26PM0.74m | 3:06AM0.30m | |||||||||
Low Tide | 2:46AM0.02m | 3:47AM0.01m | 4:56AM-0.01m | 9:20PM0.16m | 6:02AM-0.03m | 9:35PM0.15m | 7:01AM-0.05m | 9:56PM0.13m | 7:54AM-0.06m | 10:20PM0.12m | |||||||||
— | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:13 | — | — | 6:13 | — | — | |
7:15 | — | 7:14 | — | — | 7:13 | — | — | 7:13 | — | — | 7:12 | — | — | 7:10 | — | — | 7:10 | — | |
mm | — | — | — | 1 | — | — | 1 | — | — | — | 1 | 1 | — | — | 1 | — | — | — | — |
Temp °C | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 25 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 26 | 27 | 27 | 26 | 26 | 26 | 25 | 26 | 25 | 25 | 25 | 26 | 25 | 27 | 27 | 26 | 27 | 27 | 27 |
Swell 1 Height (m) Direction Period (s) | ENE 9 | SSW 14 | SSW 14 | SSW 14 | SSW 14 | SSW 14 | SSW 14 | SSW 14 | SSW 13 | SSW 13 | SSW 13 | S 18 | SSW 16 | SSW 16 | SSW 15 | SSW 15 | SSW 15 | SSW 14 | SSW 13 |
90 | 81 | 80 | 81 | 78 | 74 | 110 | 113 | 102 | 137 | 98 | 156 | 263 | 196 | 234 | 296 | 222 | 207 | 299 | |
Swell 2 Height (m) Direction Period (s) | SSW 15 | SSE 11 | SSE 11 | S 11 | SE 7 | SE 7 | SSW 19 | SSW 18 | SW 18 | SW 17 | SSW 16 | SSW 12 | SSW 12 | SSE 9 | SSE 8 | SE 9 | SSE 9 | SSE 9 | S 20 |
87 | 43 | 42 | 21 | 14 | 12 | 148 | 127 | 155 | 148 | 104 | 83 | 56 | 55 | 44 | 81 | 70 | 53 | 611 | |
Swell 3 Height (m) Direction Period (s) | S 12 | SSW 10 | SSW 10 | SE 7 | SW 21 | SW 20 | SE 7 | NE 11 | SE 8 | SE 8 | SSW 18 | SSW 16 | SSE 10 | SSW 12 | SSW 12 | SSW 11 | S 11 | SSW 11 | SSE 9 |
46 | 18 | 18 | 14 | 115 | 98 | 13 | 29 | 17 | 15 | 102 | 100 | 37 | 83 | 45 | 23 | 62 | 40 | 50 | |
Wind waves Height (m) Direction Period (s) | ENE 5 | ENE 8 | ENE 6 | ENE 5 | ENE 7 | ENE 5 | ENE 5 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 |
34 | 197 | 119 | 91 | 125 | 49 | 97 | 182 | 201 | 260 | 293 | 310 | 319 | 222 | 193 | 163 | 156 | 139 | 131 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 15 | 31 | 31 | 16 | 31 | 31 | 16 | 33 | 16 | 16 | 16 | 31 | 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











