Surf Forecasts:
Ammonias surf forecast from 10 Sep 2026:
- Best quality surf: Tuesday 15 Sep, 5AM (local time) - 2ft (0.6m), 21s period, SW 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 1.0m 8s period and expected on Tuesday (Sep 15) at 8PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Thu 10th Sep) | 2.5ft (0.7m) 13s |
| Best Surf | 5AM (Tue 15th Sep) | 2ft (0.6m) 21s |
| 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 again, but in feet, miles, and Fahrenheit.
So, first impression: it's a rough spell. We're looking at a big gap of nothing really rideable, starting from the 10th and running through to the 15th. The wind is consistently cross-onshore, making everything a choppy mess and the waves just aren't showing up.
The only break we’re watching is Ammonias, a reef setup that's fairly consistent. It's meant to have an offshore from the NW and a swell from the SSE to work its magic, which is the exact opposite of what we’re getting. Water temp is about normal for this time of year.
The first glimmer of hope shows up on the 15th of September Tuesday afternoon. The wind drops to a light breeze out of the NE at 6 mph. We’ve got a 2ft swell from the SW with a very long 19-second period (520 energy). It’s cross-shore and small, with just some light wind ripples. Not clean, but for a reef, that long period could give the waves some push and make paddling out easier. It's the closest thing to a window you’ll get in this stretch.
The real standout, for what it’s worth, is the 18th of September Friday morning. We see a 4ft swell from the SSW with a 17-second period, and the wave energy jumps up to moderate (1086). The wind is still cross-shore from the ENE at 16 mph, so there's some surface chop. It’s still marginal, but it’s the most energy in the whole forecast. This is your best bet, even if it’s not a clean session.
After that, it's back to poor surf, cross-onshore winds, and choppy water all the way to the 25th. Nothing else pops.
Focus on the 18th, maybe the 15th if you’re keen. It’s been a quiet spell, hang in there.
Rusty.
Short Range ForecastLight rain (total 3mm), mostly falling on Thu afternoon. Warm (max 27°C on Thu morning, min 24°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 3mm), mostly falling on Sun night. Warm (max 27°C on Tue afternoon, min 23°C on Sat night). Wind will be generally light. | ||||||||||||||||||
Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | ||||||||||||||
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 | ENE 8 | ENE 8 | ENE 7 | SW 16 | SW 15 | ENE 11 | ENE 10 | ENE 10 | SSW 13 | SW 15 | SSW 14 | SW 14 | ENE 6 | SW 22 | SW 21 | SW 20 | SW 19 | SSW 19 |
Wave Graph  | |||||||||||||||||||
 kJ | 178 | 191 | 256 | 254 | 198 | 229 | 436 | 173 | 128 | 98 | 104 | 82 | 97 | 69 | 227 | 224 | 392 | 384 | 465 |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore 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-off | cross | cross | cross-on |
High Tide | 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 | 1 | — | — | — | — | — | — | — | — | 3 | — | — | — | — | — | — |
Temp °C | 26 | 27 | 26 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 26 | 26 | 25 | 26 | 27 | 26 |
Feels °C | 30 | 29 | 28 | 26 | 26 | 25 | 26 | 26 | 26 | 26 | 25 | 25 | 26 | 26 | 26 | 26 | 27 | 29 | 30 |
Swell 1 Height (m) Direction Period (s) | ENE 8 | ENE 8 | SSW 12 | SW 16 | SW 16 | SW 15 | SW 15 | NE 9 | NE 9 | NE 9 | NE 9 | NE 9 | NE 9 | NE 8 | NE 8 | SW 21 | ENE 8 | ENE 8 | SSW 19 |
| kJ | 114 | 191 | 172 | 211 | 198 | 229 | 226 | 77 | 118 | 115 | 112 | 112 | 93 | 84 | 82 | 224 | 101 | 98 | 465 |
Swell 2 Height (m) Direction Period (s) | SSW 13 | SSW 13 | E 12 | E 12 | E 11 | SSW 12 | SE 8 | SW 16 | SSW 16 | ENE 9 | SW 15 | SSW 14 | SW 14 | SW 14 | SW 22 | SW 13 | SW 20 | SW 19 | SW 12 |
| kJ | 178 | 173 | 104 | 99 | 91 | 45 | 18 | 124 | 99 | 49 | 104 | 82 | 97 | 49 | 227 | 44 | 392 | 384 | 37 |
Swell 3 Height (m) Direction Period (s) | E 13 | E 12 | SW 18 | SSW 12 | SSW 12 | SW 9 | SSW 11 | SSW 13 | SSW 13 | SSW 13 | SW 12 | SE 9 | SE 9 | SE 8 | SW 14 | SE 8 | SW 12 | SW 12 | E 7 |
| kJ | 119 | 108 | 154 | 81 | 79 | 27 | 23 | 70 | 69 | 98 | 23 | 14 | 19 | 17 | 47 | 10 | 39 | 38 | 9 |
Wind waves Height (m) Direction Period (s) | — | — | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 11 | ENE 10 | ENE 10 | E 5 | ENE 9 | ENE 9 | E 4 | ENE 6 | ENE 5 | ENE 8 | — | — | ENE 7 |
| kJ | — | — | 256 | 254 | 158 | 220 | 436 | 173 | 128 | 27 | 84 | 62 | 18 | 69 | 50 | 136 | — | — | 96 |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 0 | 31 | 31 | 16 | 31 | 31 | 16 | 31 | 12 | 16 | 31 | 16 | 31 | 31 | 31 | 0 | 31 | 12 | 12 |
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)
FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Ammonias surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
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
Nearest