
Surf Forecasts:
Ammonias surf forecast from 9 Aug 2026:
- Most powerful swell: Thursday 13 Aug, 2AM (local time) - 5ft (1.5m), 16s period, S swell with 1,178 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-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 12s period and expected on Thursday (Aug 13) at 2AM.
| 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, let’s chew the fat on Ammonias. Rusty here.
To be straight with you, the next 16 days are looking like a bit of a bust. There’s a long, dry stretch of mediocre to poor conditions, and you’re gonna be twiddling your thumbs for most of it. It’s one of those blank runs that happens around here.
Kicking off on Sunday, the 9th of August, we’ve got a messy 5ft swell from the ENE with a weak, short 7-second period. Wind is a moderate cross-shore, and the water temp is about normal for the time of year. The combined energy is middling at 537, but with that wind and period, it’s not gonna be any fun. This same story drags through Monday and Tuesday, with a tiny, long-period SSW groundswell around 2ft that just doesn’t have the juice.
Wednesday the 12th shows a little pulse. By the afternoon, we’ve got 4ft from the S at a very long 18 seconds, and the energy jumps to 1188 – that’s solid. But the wind is still a moderate cross-shore, keeping a chop on the face. Thursday the 13th holds 5ft of S swell, but the wind picks up to 25 km/h from the NE, making it lumpy again.
Now, for the one brief bright spot. On Sunday the 16th of August, the swell comes up to 7ft to 8ft from the ENE, with period stretching to 11 and 13 seconds. The wind turns to a cross-offshore from the N, and the wave state cleans right up. The combined energy hits 2166 – that’s strong. This is your best bet, hands down. But that size is expert territory only; it’s too much for a beginner. The swell direction isn’t a perfect match for the break’s optimum, but with clean wind, it’s the standout for the whole outlook. It’s promising, but don’t book the week off.
Monday the 17th still has some size at 8ft, but the wind goes back to a gentle cross-shore, and it’s not as good.
After that, it’s all downhill. From Tuesday the 18th through the end of the run on Monday the 24th of August, it’s a mess of onshore and cross-on winds, tiny 2ft to 4ft waves, and weak, short periods. The energy is low, and conditions are consistently poor to marginal. It’s a long, flat patch.
So, for the experienced crew, Sunday the 16th is your window for the biggest, cleanest waves. For everyone else, this is a normal dry spell. Forecasts can always flip, but as it stands, it’s a sit-and-wait situation.
- Rusty
Short Range ForecastLight rain (total 3mm), mostly falling on Mon morning. Warm (max 27°C on Sun afternoon, min 24°C on Sun night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 27°C on Wed afternoon, min 24°C on Tue night). Wind will be generally light. | ||||||||||||||||||
Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | Friday 14 | ||||||||||||||
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 6 | ENE 7 | ENE 7 | SSW 16 | SSW 16 | SSW 15 | SSW 15 | SSW 15 | ENE 7 | S 20 | S 18 | S 18 | S 16 | S 16 | S 15 | S 15 | S 14 | S 14 | S 14 |
Wave Graph | |||||||||||||||||||
195 | 233 | 188 | 263 | 259 | 234 | 231 | 222 | 210 | 373 | 515 | 741 | 1178 | 1004 | 906 | 743 | 598 | 489 | 469 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross |
High Tide | 00:17AM0.19m | 2:05PM0.73m | 1:24AM0.22m | 2:47PM0.75m | 2:17AM0.26m | 3:26PM0.74m | 3:06AM0.30m | 4:02PM0.71m | 3:54AM0.34m | 4:34PM0.66m | 4:44AM0.37m | 5:03PM0.59m | |||||||
Low Tide | 9:20PM0.16m | 6:02AM-0.03m | 9:35PM0.15m | 7:01AM-0.05m | 9:56PM0.13m | 7:54AM-0.06m | 10:20PM0.12m | 8:43AM-0.04m | 10:44PM0.10m | 9:30AM-0.00m | 11:09PM0.08m | 10:17AM0.05m | 11:35PM0.07m | ||||||
— | 6:11 | — | — | 6:13 | — | — | 6:13 | — | — | 6:13 | — | — | 6:13 | — | — | 6:13 | — | — | |
7:13 | — | 7:12 | — | — | 7:10 | — | — | 7:10 | — | — | 7:09 | — | — | 7:08 | — | — | 7:08 | — | |
mm | — | — | — | — | 2 | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 25 | 26 | 27 | 25 | 26 | 26 | 25 | 26 | 27 | 25 | 26 | 27 | 25 | 27 | 27 | 25 | 27 | 27 | 25 |
Feels °C | 25 | 26 | 27 | 25 | 27 | 27 | 26 | 26 | 27 | 25 | 26 | 25 | 24 | 26 | 26 | 25 | 25 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | SSW 13 | SSW 13 | S 18 | SSW 16 | SSW 16 | SSW 15 | SSW 15 | SSW 15 | SSW 14 | SSW 13 | SSW 13 | S 18 | S 16 | S 16 | S 15 | S 15 | S 14 | S 14 | S 14 |
137 | 98 | 156 | 263 | 259 | 234 | 231 | 222 | 210 | 299 | 289 | 741 | 1178 | 1004 | 906 | 743 | 598 | 489 | 469 | |
Swell 2 Height (m) Direction Period (s) | SW 17 | SSW 16 | SSW 12 | SE 10 | SE 9 | SE 8 | SE 9 | SSE 9 | SSE 9 | S 20 | S 18 | SSW 13 | W 12 | W 12 | SE 9 | SE 12 | SE 12 | SE 12 | SE 13 |
148 | 104 | 83 | 46 | 42 | 33 | 64 | 54 | 53 | 373 | 515 | 289 | 25 | 25 | 14 | 23 | 22 | 36 | 60 | |
Swell 3 Height (m) Direction Period (s) | SE 8 | SSW 18 | SSW 16 | SSW 12 | SSW 12 | SSW 11 | SSW 11 | S 11 | SSW 11 | SE 9 | SE 9 | SE 8 | WNW 12 | SW 19 | W 12 | W 12 | W 12 | W 11 | W 11 |
17 | 102 | 100 | 82 | 81 | 24 | 23 | 62 | 41 | 37 | 36 | 35 | 27 | 14 | 10 | 10 | 11 | 22 | 21 | |
Wind waves Height (m) Direction Period (s) | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 6 | ENE 6 | ENE 6 | E 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 8 | ENE 8 |
195 | 233 | 188 | 222 | 228 | 193 | 186 | 181 | 181 | 135 | 139 | 123 | 176 | 170 | 177 | 247 | 319 | 322 | 408 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 31 | 16 | 16 | 31 | 16 | 16 | 31 | 31 | 16 | 31 | 16 | 16 | 16 | 31 | 31 | 31 | 31 | 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











