Surf Forecasts:
Ammonias surf forecast from 23 Aug 2026:
- Most powerful swell: Thursday 27 Aug, 2PM (local time) - 3.5ft (1.1m), 17s period, S swell with 702 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 1.1m 17s and forecast to arrive on Thursday (Aug 27) at 2PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 12s period and expected on Saturday (Aug 22) at 11PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 2PM (Thu 27th Aug) | 3.5ft (1.1m) 17s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
Alright, folks, let’s be real – the surf outlook is looking grim for a good while. The first thing even worth talking about at Ammonias (reef) pops up on Saturday afternoon, August 22nd, and I’m being generous.
That Saturday, we’re looking at a 6ft swell from the ENE, but with a short 7-second period. The wind is cross-shore with a moderate breeze, so expect a bumpy, chopped-up surface. The combined energy is moderate at 579, but the conditions are questionable. You could probably find a wave, but it’s not the kind of day you’d mark on the calendar.
After that, it’s a desert. Sunday the 23rd through Tuesday the 25th is all poor conditions. The swell stays, but dirty wind ruins it.
Then things get weird. Around Wednesday the 26th and Thursday the 27th, the swell drops to 3-3ft, but the period goes long – 14 to 17 seconds from the south. This is real groundswell, with strong energy (a reading of 923). The catch is it’s tiny. And the wind is still a moderate cross-shore, so it’s not glass clean. You might catch a little, super-mellow wave on a longboard, but it’s marginal.
We get another messy stretch of short-period, onshore windswell until the end of the month. Then, on Tuesday, September 1st, the south swell comes back with a very long 18-19 second period. The water temp is average for this time of year. The combined energy is strong at 1113 the next day, but the height is only 3ft. The wind does ease to a light breeze on Wednesday the 2nd, which would make the surface nice, but you’re chasing tiny lines again. Marginal.
We close out the forecast with more poor, short-period conditions and onshore wind into the first week of September. Sunday, September 6th shows a 6ft swell from the ENE with a better 11-second period and very strong energy (1054), but the wind is cross and moderate, so expect a lumpy, bumpy surface. Still borderline.
The Best You’ll Get: Honestly, the most interesting, but still not great, window is the longer period south swell around Thursday, August 27th and Tuesday, September 1st. The long period means better shape, and at a reef break like Ammonias, it’ll have more punch for its size than the short-period junk. But it’s so small it’s barely breaking. Wednesday, September 2nd might be your best bet if you just want a clean, glassy paddle, but you won’t be getting barreled.
We’ve got some pretty big gaps with zero good options in this 16-day outlook. It’s a dry spell, and for this area, that happens. Don’t lose hope – forecasts can change, but for now, it’s a tough stretch.
Rusty
Short Range ForecastLight rain (total 8mm), mostly falling on Sun night. Warm (max 27°C on Sat afternoon, min 25°C on Sat night). Wind will be generally light. | Days 5-7 Weather SummarySome drizzle, heaviest during Fri morning. Warm (max 27°C on Tue afternoon, min 24°C on Tue night). Wind will be generally light. | |||||||||||||||||||
Sat 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | ||||||||||||||
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) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | E 7 | E 7 | SSW 14 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 |
Wave Graph | ||||||||||||||||||||
255 | 301 | 278 | 247 | 277 | 299 | 316 | 261 | 270 | 278 | 247 | 276 | 395 | 573 | 699 | 553 | 465 | 334 | 320 | 294 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross | cross | cross-on | cross | cross | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross | cross |
High Tide | 00:35AM0.22m | 1:46PM0.62m | 1:16AM0.25m | 2:19PM0.63m | 1:51AM0.28m | 2:48PM0.64m | 2:25AM0.31m | 3:14PM0.64m | 3:02AM0.35m | 3:38PM0.62m | 3:40AM0.38m | 4:02PM0.59m | 4:22AM0.42m | |||||||
Low Tide | 9:13PM0.18m | 5:45AM0.08m | 9:16PM0.18m | 6:37AM0.05m | 9:23PM0.17m | 7:21AM0.04m | 9:34PM0.16m | 8:01AM0.03m | 9:50PM0.13m | 8:40AM0.04m | 10:08PM0.11m | 9:19AM0.06m | 10:29PM0.08m | |||||||
— | — | 6:16 | — | — | 6:16 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | |
7:01 | — | — | 7:01 | — | — | 7:00 | — | — | 7:00 | — | — | 6:59 | — | — | 6:58 | — | — | 6:57 | — | |
mm | — | — | — | — | 1 | 2 | 1 | 4 | — | — | — | — | — | — | — | — | — | 1 | — | — |
Temp °C | 27 | 26 | 27 | 27 | 25 | 26 | 27 | 25 | 26 | 27 | 25 | 26 | 26 | 24 | 26 | 26 | 25 | 26 | 26 | 25 |
Feels °C | 28 | 27 | 28 | 27 | 25 | 27 | 28 | 26 | 26 | 27 | 25 | 25 | 25 | 24 | 26 | 26 | 25 | 26 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | SW 16 | SSW 16 | SSW 15 | SSW 15 | SSW 14 | SSW 14 | SE 9 | SE 8 | SE 8 | SSW 16 | SSE 9 | SSW 14 | S 18 | S 19 | S 17 | S 17 | S 15 | S 14 | S 14 | S 14 |
251 | 212 | 196 | 188 | 183 | 163 | 83 | 67 | 69 | 193 | 49 | 276 | 395 | 573 | 699 | 553 | 465 | 334 | 320 | 294 | |
Swell 2 Height (m) Direction Period (s) | W 10 | WNW 11 | S 13 | SE 12 | SE 12 | SE 10 | SSW 13 | SSW 12 | SSW 16 | SSE 8 | SSW 12 | S 18 | SSW 13 | SSW 13 | SSW 12 | S 12 | SSW 11 | SSW 11 | E 15 | E 14 |
56 | 98 | 130 | 86 | 90 | 60 | 156 | 121 | 201 | 47 | 86 | 167 | 133 | 135 | 79 | 73 | 39 | 40 | 107 | 96 | |
Swell 3 Height (m) Direction Period (s) | SSE 15 | S 14 | SE 9 | SSE 13 | S 13 | S 12 | SSW 18 | SSW 16 | SSW 12 | SSW 12 | SSW 15 | SE 8 | SSE 9 | SE 8 | NNE 8 | NNE 8 | NNE 8 | NNE 7 | SSW 19 | SSW 10 |
73 | 107 | 52 | 59 | 89 | 78 | 61 | 153 | 83 | 85 | 121 | 35 | 30 | 29 | 13 | 13 | 19 | 18 | 35 | 18 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | E 7 | E 7 | E 7 | E 7 | ENE 7 | ENE 6 | ENE 6 | E 6 | E 6 | E 6 | ENE 6 | E 6 |
255 | 301 | 278 | 247 | 277 | 299 | 316 | 261 | 270 | 278 | 247 | 206 | 180 | 155 | 145 | 115 | 91 | 120 | 147 | 206 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 16 | 16 | 16 | 33 | 31 | 33 | 16 | 16 | 31 | 31 | 16 | 31 | 16 | 16 | 31 | 16 | 16 | 31 | 16 | 16 |
Best forecast wave conditions in Kaua'i | ||||||||||||||||||||
Best forecast wave conditions in United States | ||||||||||||||||||||
Header Global | ||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
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











