
Surf Forecasts:
Ammonias surf forecast from 10 Sep 2026:
- Best quality surf: Thursday 10 Sep, 2AM (local time) - 2.5ft (0.7m), 13s period, SSW swell with cross-offshore winds.
- Most powerful swell: Wednesday 16 Sep, 2PM (local time) - 3ft (0.9m), 18s period, SSW swell with 541 kJ wave energy.
- Next surfable swell (1★+): Thursday 10 Sep, 2AM (local time) - 2.5ft (0.7m), 13s period with SSW 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 Thursday (Sep 10) at 2AM. The primary swell is predicted to be 0.7m and 13s period with a secondary swell of 0.9m and 8s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Ammonias in the next 16 days are 0.9m 18s and forecast to arrive on Wednesday (Sep 16) at 2PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 8s period and expected on Monday (Sep 14) at 5PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Thu 10th Sep) | 2.5ft (0.7m) 13s |
| Best Surf | 2AM (Thu 10th Sep) | 2.5ft (0.7m) 13s |
| Most Powerful | 2PM (Wed 16th Sep) | 3ft (0.9m) 18s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright, Rusty here with the lowdown. We've got a sixteen-day forecast for Ammonias, and it's a mixed bag with one golden window.
Water temp is holding around 80°, right where it should be.
Clear standout is Wednesday, September 9th. We’ve got a small 3ft swell from the SSW, but the wind is dead glass. That’s the ticket for clean, smooth waves. The energy is solid (418), and it’s the only day that looks really good.
Then comes the bad news. From Thursday the 10th right up to Tuesday the 22nd, it's a long stretch of poor surf. The wind is blowing cross-on or cross-shore from the east and northeast, turning everything into a choppy mess. Swell sizes fluctuate, but the quality is shot. Some of that swell is long-period (15-22 seconds), which would be epic, but without clean wind, it doesn’t matter. You'll see moderate to strong energy readings (like 658, 667, 776, 934), but those numbers just tell you the ocean is powerful and messy—more of a kite-surfing scene than a clean wave.
There’s a tiny window late on Wednesday the 23rd. The wind goes glassy again, but the swell is only 2ft from the SSW. It’s rideable on a longboard, but nothing to get too excited about.
So, mark your calendar for the 9th. It’s your only real shot at something clean. The rest is a write-off.
Rusty.
Short Range ForecastLight rain (total 5mm), mostly falling on Thu night. Warm (max 27°C on Wed afternoon, min 24°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummarySome drizzle, heaviest during Sat night. Warm (max 26°C on Mon afternoon, min 24°C on Sat night). Wind will be generally light. | |||||||||||||||||||
Wed 9 | Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | ||||||||||||||
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) | SSW 13 | SSW 13 | ENE 8 | ENE 7 | ENE 7 | SW 16 | ENE 8 | ENE 11 | ENE 10 | ENE 10 | ENE 9 | SW 15 | E 9 | SW 14 | SW 14 | SW 22 | SW 21 | SW 20 | SW 19 | SSW 19 |
Wave Graph | ||||||||||||||||||||
253 | 178 | 191 | 237 | 218 | 198 | 229 | 379 | 173 | 169 | 115 | 104 | 40 | 97 | 49 | 227 | 224 | 392 | 384 | 465 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | cross-off | cross-on | cross-on | cross | cross-on | cross | cross-on | cross-on | cross-on | cross | cross-on | cross | cross-on | cross | cross | cross | cross-on | cross-on | cross |
High Tide | 2:54PM0.66m | 3:04AM0.41m | 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 | |||||||
Low Tide | 9:25PM0.09m | 8:43AM0.05m | 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 | |||||||
— | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:22 | — | — | 6:24 | — | — | |
6:45 | — | — | 6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:42 | — | — | 6:40 | — | — | 6:39 | — | |
mm | — | — | — | 2 | 3 | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — |
Temp °C | 27 | 26 | 27 | 26 | 25 | 25 | 25 | 24 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 26 | 25 | 26 | 27 | 26 |
Feels °C | 30 | 30 | 29 | 27 | 26 | 25 | 25 | 24 | 26 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 28 | 30 | 29 |
Swell 1 Height (m) Direction Period (s) | ENE 9 | ENE 8 | SSW 13 | SSW 12 | SW 16 | SW 16 | SW 15 | SW 15 | NE 8 | NE 9 | NE 9 | NE 9 | NE 9 | NE 9 | NE 8 | SW 22 | SW 21 | SW 20 | SW 19 | NE 7 |
165 | 114 | 173 | 172 | 211 | 198 | 229 | 226 | 74 | 84 | 112 | 110 | 107 | 115 | 100 | 227 | 224 | 392 | 384 | 77 | |
Swell 2 Height (m) Direction Period (s) | SSW 13 | SSW 13 | E 12 | E 12 | E 12 | E 11 | SSW 12 | SE 8 | SW 16 | SSW 16 | SSW 13 | SW 15 | E 9 | SW 14 | SE 8 | SW 14 | SSE 8 | SSE 8 | SSE 8 | SSW 19 |
253 | 178 | 108 | 104 | 99 | 91 | 45 | 34 | 124 | 99 | 98 | 104 | 40 | 97 | 17 | 47 | 26 | 23 | 22 | 465 | |
Swell 3 Height (m) Direction Period (s) | NW 9 | E 13 | SSW 17 | SW 18 | SSW 12 | SSW 12 | SW 9 | SSW 11 | SSW 13 | SSW 13 | SW 16 | SE 8 | SE 9 | SE 9 | SW 14 | SE 8 | SW 13 | SW 12 | SW 12 | E 8 |
68 | 119 | 186 | 154 | 81 | 79 | 27 | 23 | 70 | 69 | 64 | 15 | 31 | 27 | 49 | 16 | 44 | 39 | 38 | 29 | |
Wind waves Height (m) Direction Period (s) | — | — | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 11 | ENE 10 | ENE 10 | ENE 9 | ENE 9 | — | E 4 | ENE 5 | NE 8 | NE 8 | NE 8 | NE 7 | — |
— | — | 191 | 237 | 218 | 158 | 226 | 379 | 173 | 169 | 115 | 84 | — | 25 | 45 | 158 | 129 | 96 | 91 | — | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 0 | 0 | 31 | 31 | 16 | 31 | 31 | 16 | 16 | 12 | 12 | 31 | 12 | 31 | 31 | 15 | 1 | 12 | 12 | 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










