Surf Forecasts:
Ammonias surf forecast from 30 Aug 2026:
- Most powerful swell: Saturday 5 Sep, 2PM (local time) - 8ft (2.5m), 8s period, ENE swell with 886 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 2.5m 8s and forecast to arrive on Saturday (Sep 05) at 2PM. Winds are predicted to be cross-shore at the time the swell arrives.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 2PM (Sat 5th Sep) | 8ft (2.5m) 8s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Right. Rusty here. Let’s have a look at what’s cookin’ over the next couple weeks.
Forecast for Ammonias, a reef setup. Early on, we’re stuck in a pretty grim run. From Sunday 30 August right through to Thursday 11 September, the conditions are just not coming together. It’s a long stretch of poor surf quality. You’ve got a moderate breeze blowing cross-shore or cross-onshore, and a cross-chop or lumpy sea state for almost every session. The combined wave energy is moderate for much of that time (for example 729 on the Sunday morning), but the winds ruin it.
A couple of days do show a small window of something better. Wednesday morning 9 September sees the swell pushing up around 8ft from ENE with a period of 10 seconds, and gentle cross-onshore winds keeping it only fairly choppy. The afternoon then improves to 10ft ENE swell, with a gentle cross-shore breeze and only slight cross-chop. Combined energy jumps to 1962, which is strong. This is the best looking stretch of the whole forecast. It’s big – over 8ft – so this is expert territory only. Not for beginners. The swell direction of ENE doesn’t match the optimum SSE direction for this break, so the waves won’t be perfectly groomed, but the size and lack of strong wind make it the standout.
Then Thursday 10 September morning offers a brief moment of interest: the wind goes light and offshore from the SSE at 10 km/h (6 mph) on an 8ft ENE swell. That’s clean face potential, but the period is only 9 seconds so it’s a bit short and fat. Still, a morning of clean 8ft is worth a look for the experienced crew. Crowds are possible here, so go early.
After that, it drops right off again. Saturday 12 September sees tiny 2ft–2ft SSW swells and moderate cross-onshore chop. The final days are weak or messy. Monday 14 September has a super long period SSW groundswell at 21 seconds but only 1ft – barely a ripple. Not worth paddling out for.
Overall, the first week and a half is a write-off. The real play is Wednesday afternoon 9 September and the Thursday morning 10 September. The rest is a bust.
- Rusty
Short Range ForecastLight rain (total 9mm), mostly falling on Sat night. Warm (max 26°C on Sun morning, min 24°C on Sun night). Mainly fresh winds. | Days 5-7 Weather SummaryHeavy rain (total 21mm), heaviest during Thu morning. Warm (max 26°C on Wed morning, min 24°C on Thu night). Mainly fresh winds. | ||||||||||||||||||
Sunday 30 | Monday 31 | Tuesday 1 | Wednesday 2 | Thursday 3 | Friday 4 | ||||||||||||||
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 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | S 16 | S 16 | S 15 | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 8 | ENE 8 |
Wave Graph | |||||||||||||||||||
456 | 387 | 344 | 301 | 432 | 400 | 451 | 382 | 373 | 475 | 427 | 406 | 352 | 283 | 331 | 305 | 356 | 411 | 540 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross | cross | cross | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross | cross | cross | cross |
High Tide | 5:07AM0.46m | 4:47PM0.49m | 5:58AM0.49m | 5:08PM0.42m | 6:57AM0.52m | 5:24PM0.35m | 8:09AM0.55m | 5:17PM0.30m | 9:35AM0.57m | 10:57AM0.61m | |||||||||
Low Tide | 10:52PM0.06m | 10:51AM0.15m | 11:17PM0.04m | 11:48AM0.20m | 11:45PM0.03m | 1:02PM0.26m | 00:18AM0.03m | 3:05PM0.29m | 1:01AM0.04m | 2:01AM0.05m | 3:24AM0.06m | ||||||||
— | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | 6:20 | — | — | |
6:55 | — | 6:54 | — | — | 6:54 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | — | 6:51 | — | |
mm | 2 | 1 | — | 2 | 1 | 1 | 1 | — | 1 | 3 | 2 | 2 | 4 | 5 | 1 | 1 | 1 | 2 | 2 |
Temp °C | 25 | 26 | 26 | 26 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 26 | 25 | 26 | 25 | 26 | 25 | 25 |
Feels °C | 25 | 25 | 25 | 26 | 25 | 25 | 24 | 25 | 25 | 24 | 26 | 25 | 26 | 25 | 25 | 24 | 24 | 23 | 24 |
Swell 1 Height (m) Direction Period (s) | S 12 | S 12 | S 12 | SSW 15 | S 11 | S 11 | SSW 19 | S 18 | S 18 | S 17 | S 16 | S 16 | S 15 | S 14 | S 14 | S 13 | S 13 | S 13 | E 13 |
141 | 100 | 100 | 196 | 85 | 82 | 391 | 314 | 314 | 373 | 427 | 406 | 352 | 268 | 243 | 285 | 222 | 165 | 173 | |
Swell 2 Height (m) Direction Period (s) | SSW 17 | SSW 16 | SSW 16 | S 11 | SSW 15 | SSW 14 | S 10 | S 10 | S 12 | SSE 10 | S 10 | SSE 10 | S 11 | S 10 | E 12 | E 12 | E 14 | E 14 | S 13 |
186 | 171 | 162 | 89 | 144 | 180 | 74 | 46 | 105 | 34 | 53 | 31 | 86 | 75 | 77 | 44 | 142 | 131 | 162 | |
Swell 3 Height (m) Direction Period (s) | E 12 | E 12 | ENE 11 | ENE 11 | SSW 21 | ENE 10 | SW 14 | SSW 14 | SW 14 | SW 14 | SSW 13 | S 12 | E 13 | E 13 | SSE 10 | SE 13 | SE 12 | SE 12 | SE 12 |
75 | 71 | 41 | 40 | 85 | 33 | 52 | 115 | 53 | 52 | 17 | 25 | 56 | 84 | 33 | 43 | 53 | 90 | 66 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 8 | ENE 8 |
456 | 387 | 344 | 301 | 432 | 400 | 451 | 382 | 373 | 475 | 392 | 383 | 311 | 283 | 331 | 305 | 356 | 411 | 540 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 33 | 33 | 16 | 31 | 16 | 16 | 16 | 31 | 16 | 16 | 31 | 16 | 33 | 31 | 14 | 31 | 31 | 31 |
Best forecast wave conditions in Kaua'i | |||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||
Header Global | |||||||||||||||||||
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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











