
Surf Forecasts:
Ammonias surf forecast from 9 Jul 2026:
- Most powerful swell: Sunday 12 Jul, 11PM (local time) - 7.5ft (2.3m), 8s period, ENE swell with 613 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 2.3m 8s and forecast to arrive on Sunday (Jul 12) at 11PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.8m 15s period and expected on Wednesday (Jul 15) at 2AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 11PM (Sun 12th Jul) | 7.5ft (2.3m) 8s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
G’day, I’m Rusty. Let’s have a look at what’s coming for the Ammonias area over the next couple of weeks. First up, I’ll be straight with you: the first week is pretty grim. There’s plenty of ENE wind that keeps the surf lumpy and chopped up.
Starting Thursday, the 9th of July, we’ve got swell running about 7 ft with a short period of 8 seconds from the ENE, but there’s a fresh cross-onshore wind making it a real mess. Water temperature is 79°F, which is about normal for this time of year. Through Thursday afternoon and into Friday the 10th, the swell drops to about 6 ft, period goes to 7 seconds, and the wind stays moderate cross-shore. Saturday the 11th has a bit more energy (combined swell energy 690–721), but still cross-shore and short period. Sunday the 12th sees energy climb (800–907), but it’s cross-on and choppy with rain showers. This same pattern—moderate cross-shore or cross-on wind, short-period swell from 6 ft to 7 ft—keeps repeating through Monday the 13th and Tuesday the 14th. Tuesday afternoon finally gets a “marginal” tag, but the water’s still messy.
All through this stretch, the period is mostly 7 to 8 seconds, so it’s short-period windswell with no real shape. If you’ve got a kite and the wind is 15–19 mph cross-shore, that might be more your thing, but for a surfboard, it’s pretty rough.
Things shift a bit on Monday the 20th of July. The morning still has that ENE wind and 6 ft short-period swell, but by Monday afternoon, a new, very long-period groundswell from the south at 17 seconds shows up, though it’s only 2 ft. Combined energy sits at 697. The wind drops to a moderate 12 mph cross-shore from the NE. This is where it gets interesting. Tuesday the 21st of July brings that E groundswell up: 3 ft in the morning and 4 ft in the afternoon, with a still-impressive period of 16–17 seconds. Combined energy jumps into the strong range (1192–1241), and the wind stays moderate cross-shore. These are the standout days. That period means real energy and push in the water, and at a reef setup like Ammonias, it could wrap in nicely. Just be aware that long-period swell can break straight at beach breaks, but the reef might help. The wind isn’t glassy, but it’s far better than the rest.
Wednesday the 22nd still has some of that E groundswell at 3 ft with 14–15 second period, but by Thursday the 23rd, it fades. Thursday and Friday the 24th go back to short-period windswell and cross-on winds—not worth your time.
So, to wrap it up: a long stretch of poor conditions from the 9th through the 20th of July, then a short window on Monday afternoon the 20th, Tuesday the 21st, and Wednesday the 22nd, where a long-period groundswell from the east offers the best surf of the whole forecast. Tuesday the 21st is the pick, with 3–4 ft and 16–17 second period, and the reef at Ammonias should give you the best chance at a decent wave. It’s not perfect wind, but it’s head and shoulders above everything else.
Rusty.
Short Range ForecastLight rain (total 8mm), mostly falling on Thu morning. Warm (max 25°C on Thu morning, min 24°C on Thu morning). Mainly fresh winds. | Days 4-6 Weather SummaryModerate rain (total 12mm), heaviest on Sun morning. Warm (max 26°C on Tue afternoon, min 23°C on Mon night). Mainly fresh winds. | ||||||||||||||||||||
Thursday 9 | Friday 10 | Saturday 11 | Sunday 12 | Monday 13 | Tuesday 14 | Wednesday 15 | |||||||||||||||
AM | 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 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | SSW 16 |
Wave Graph | |||||||||||||||||||||
536 | 509 | 415 | 328 | 330 | 303 | 432 | 379 | 359 | 397 | 536 | 596 | 421 | 345 | 305 | 305 | 294 | 294 | 310 | 271 | 314 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross | cross | cross | cross | cross-on | cross | cross-on | cross-on | cross | cross-on |
High Tide | 12:45PM0.59m | 9:34PM0.22m | 1:33PM0.67m | 11:46PM0.18m | 2:19PM0.73m | 1:06AM0.18m | 3:04PM0.77m | 2:08AM0.19m | 3:47PM0.78m | 3:04AM0.21m | 4:29PM0.77m | 3:58AM0.23m | 5:08PM0.73m | 4:55AM0.26m | |||||||
Low Tide | 9:16PM0.22m | 5:17AM-0.06m | 9:34PM0.17m | 6:09AM-0.08m | 10:03PM0.14m | 7:03AM-0.10m | 10:34PM0.12m | 7:55AM-0.11m | 11:06PM0.11m | 8:46AM-0.10m | 11:38PM0.10m | 9:34AM-0.07m | 00:10AM0.09m | ||||||||
6:00 | — | — | 6:00 | — | — | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | |
— | 7:23 | — | — | 7:23 | — | — | 7:23 | — | — | 7:23 | — | — | 7:23 | — | — | 7:22 | — | — | 7:22 | — | |
mm | 4 | 1 | 1 | — | — | 1 | — | — | 1 | 3 | 3 | 3 | — | — | 3 | — | — | — | — | — | — |
Temp °C | 25 | 25 | 24 | 25 | 25 | 24 | 25 | 25 | 24 | 25 | 25 | 24 | 25 | 25 | 24 | 25 | 26 | 24 | 25 | 26 | 25 |
Feels °C | 24 | 24 | 23 | 24 | 24 | 23 | 23 | 23 | 23 | 24 | 23 | 23 | 23 | 23 | 23 | 24 | 25 | 23 | 24 | 25 | 25 |
Swell 1 Height (m) Direction Period (s) | S 12 | S 12 | S 12 | S 12 | S 11 | SW 19 | SSW 18 | SW 18 | SW 17 | SSW 16 | SSW 16 | SW 16 | SSW 15 | SSW 14 | SW 14 | SW 14 | SW 14 | W 15 | W 15 | W 15 | W 15 |
151 | 108 | 106 | 98 | 66 | 184 | 214 | 316 | 309 | 326 | 322 | 353 | 279 | 268 | 206 | 189 | 186 | 298 | 287 | 279 | 275 | |
Swell 2 Height (m) Direction Period (s) | SE 8 | SE 8 | W 13 | W 13 | W 13 | S 11 | S 12 | W 13 | S 13 | SSE 12 | SSE 12 | SSE 12 | W 19 | SSE 11 | W 17 | W 16 | W 16 | SSW 13 | SW 13 | SSW 12 | SSW 16 |
11 | 16 | 30 | 28 | 55 | 60 | 44 | 54 | 51 | 52 | 49 | 48 | 112 | 85 | 142 | 257 | 248 | 109 | 162 | 103 | 314 | |
Swell 3 Height (m) Direction Period (s) | W 14 | W 14 | SSE 8 | W 15 | SE 8 | W 14 | W 14 | SE 9 | SE 9 | SE 8 | W 12 | SE 8 | SSE 12 | W 18 | SSE 11 | SSW 19 | SW 19 | SSW 17 | SSW 18 | SSW 18 | SSE 6 |
15 | 32 | 6 | 38 | 17 | 58 | 61 | 26 | 28 | 25 | 26 | 25 | 47 | 150 | 40 | 146 | 93 | 200 | 123 | 184 | 16 | |
Wind waves Height (m) Direction Period (s) | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 |
536 | 509 | 415 | 328 | 330 | 303 | 432 | 379 | 359 | 397 | 536 | 596 | 421 | 345 | 305 | 305 | 294 | 294 | 310 | 271 | 306 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 38 | 46 | 16 | 31 | 31 | 33 | 31 | 33 | 16 | 31 | 38 | 16 | 33 | 31 | 16 | 31 | 31 | 16 | 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










