
Surf Forecasts:
Ammonias surf forecast from 8 Aug 2026:
- Most powerful swell: Thursday 13 Aug, 5AM (local time) - 5ft (1.5m), 16s period, S swell with 1,164 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 5AM. 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 | 5AM (Thu 13th Aug) | 5ft (1.5m) 16s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
G’day, Rusty here. Let me tell you, this forecast is a tough one to write. The next week and a half is looking pretty bleak for a decent paddle. The wind is stuck in that ENE/NE pattern, which means it’s mostly cross-shore or cross-on at Ammonias, and that’s just chopping everything up. We’ve got a lot of poor conditions and low scores on the board for the first week.
The one real standout doesn’t show its face until Sunday the 16th. That Saturday the 15th is going to be a mix of building but messy swell—cross-shore winds and lumpy conditions with waves pushing 10ft to 12ft, and the energy is climbing fast. But it’s the Sunday morning that has me interested. We’ve got a 15ft SSE swell with a 14-second period, and the energy reading is through the roof at 9119. That’s a serious pulse of groundswell. The problem is the wind is still cross-shore, so it won’t be glassy, but it’s the biggest and most powerful swell we’re going to see in this whole window. The swell direction is dead on the money for Ammonias’ optimum from the SSE, too. That’s the one to get excited about, but it’s a big one—15ft is expert territory, way over the 8ft mark. The afternoon drops back to 10ft at 11 seconds, which is a bit more manageable but still a heavy, powerful wave. This is a day for the experienced crew only.
Before that, there’s a glimmer on Wednesday the 12th. The swell is smaller, but the period is a long 18 seconds, and the energy is moderate to strong at 1238. The waves are only 4ft, so it’s not a stand-out, but that long period is nice. It’ll be breaking cleanest at a reef like this, but the cross-shore wind is still going to put a bit of chop on the face. It’s a marginal call, not a headline act.
After that Sunday the 16th pulse, the energy drops off hard. The following week is back to smaller, short-period ENE windswell, mostly in the 4ft to 6ft range, with periods around 6 to 8 seconds. That’s weak, choppy, and not worth paddling out for. The wind stays cross-shore, and the conditions just stay messy. There’s another small pulse of SSW swell on the 22nd, but it’s weak and cross-on, so don’t get your hopes up.
So to sum it up: the first two weeks are a write-off for the most part. The standout is Sunday morning the 16th—that’s the one. Big SSE groundswell, decent period, and the energy is massive. It’s a beast, but it’s the only real surf on the horizon worth getting excited about. The rest is a battle with the wind and messy, short-period slop. Keep the board in the car for that Sunday, and maybe give the kites a thought for the rest, because that cross-shore is going to be more fun for them than for us.
Rusty.
Short Range ForecastLight rain (total 6mm), mostly falling on Fri night. Warm (max 26°C on Sat morning, min 24°C on Fri night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 2mm), mostly falling on Mon night. Warm (max 27°C on Tue afternoon, min 24°C on Tue night). Mainly fresh winds. | ||||||||||||||||||
Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | ||||||||||||||
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 19 | SSW 14 | SW 18 | ENE 6 | ENE 7 | ENE 7 | SSW 16 | ENE 7 | ENE 7 | ENE 7 | SSW 15 | E 7 | S 20 | S 18 | S 18 | S 16 | S 16 | S 15 | S 15 |
Wave Graph | |||||||||||||||||||
148 | 156 | 172 | 188 | 198 | 215 | 263 | 269 | 259 | 231 | 222 | 210 | 373 | 515 | 741 | 1029 | 1004 | 784 | 743 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | cross | cross | cross-on | cross | cross-on | cross-on | cross | cross-on | cross-on | cross | cross | cross-on | cross | cross | cross | cross | cross |
High Tide | 1:18PM0.69m | 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 | |||||||
Low Tide | 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 | 8:43AM-0.04m | 10:44PM0.10m | 9:30AM-0.00m | 11:09PM0.08m | |||||||
— | 6:11 | — | — | 6:11 | — | — | 6:13 | — | — | 6:13 | — | — | 6:13 | — | — | 6:13 | — | — | |
7:13 | — | 7:13 | — | — | 7:12 | — | — | 7:10 | — | — | 7:10 | — | — | 7:09 | — | — | 7:08 | — | |
mm | 1 | 2 | — | — | — | — | 1 | 2 | — | 2 | — | — | — | — | — | — | — | — | — |
Temp °C | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 27 | 25 | 26 | 26 | 25 | 27 | 27 | 25 |
Feels °C | 25 | 26 | 25 | 25 | 26 | 25 | 25 | 26 | 26 | 26 | 27 | 27 | 25 | 24 | 25 | 24 | 26 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | 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 | SSW 13 | S 18 | S 16 | S 16 | S 15 | S 15 |
110 | 156 | 102 | 137 | 98 | 156 | 263 | 259 | 234 | 231 | 222 | 210 | 299 | 289 | 741 | 1029 | 1004 | 784 | 743 | |
Swell 2 Height (m) Direction Period (s) | SSW 19 | SSW 18 | SW 18 | SW 17 | SSW 16 | SSW 12 | SSW 12 | SSW 12 | SSE 10 | SSE 9 | SSE 9 | SSE 9 | S 20 | S 18 | SSW 13 | W 12 | W 12 | SE 10 | W 12 |
148 | 127 | 155 | 148 | 104 | 83 | 56 | 79 | 37 | 54 | 53 | 52 | 373 | 515 | 289 | 25 | 11 | 23 | 10 | |
Swell 3 Height (m) Direction Period (s) | SE 7 | NE 11 | SE 8 | SE 8 | SSW 18 | SSW 16 | SSE 10 | SSE 9 | SSW 12 | SSW 11 | S 11 | SSW 11 | SE 9 | W 12 | SE 9 | W 9 | SW 19 | W 12 | SW 18 |
12 | 29 | 17 | 16 | 102 | 100 | 37 | 34 | 45 | 23 | 62 | 41 | 37 | 26 | 38 | 2 | 14 | 11 | 13 | |
Wind waves Height (m) Direction Period (s) | ENE 5 | ENE 6 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 6 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | ENE 6 | E 7 | ENE 6 | ENE 6 | ENE 7 | ENE 7 | ENE 7 |
59 | 122 | 172 | 188 | 198 | 215 | 233 | 269 | 259 | 215 | 197 | 206 | 150 | 196 | 170 | 212 | 277 | 286 | 529 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 31 | 31 | 16 | 31 | 16 | 16 | 31 | 16 | 16 | 31 | 16 | 16 | 31 | 16 | 14 | 31 | 31 | 31 |
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











