
Surf Forecasts:
Ammonias surf forecast from 20 Jul 2026:
- Most powerful swell: Sunday 26 Jul, 5PM (local time) - 4.5ft (1.4m), 16s period, E swell with 984 kJ wave energy.
Best Forecast Surf Conditions for Ammonias this week:
The most powerful waves expected at Ammonias in the next 16 days are 1.4m 16s and forecast to arrive on Sunday (Jul 26) at 5PM. 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 | 5PM (Sun 26th Jul) | 4.5ft (1.4m) 16s |
Table - best surf conditions forecast for Ammonias over the next 16 days.
The Lowdown
G’day, Rusty here. Let’s get into it. We’ve got a mixed bag of a 16-day window at Ammonias, a reef break that can handle some juice but is pretty exposed. The water temp’s sitting about average for the time of year, nothing to write home about.
Straight up, there’s no clean, glassy surf on offer here. The whole period is plagued by cross-shore or cross-onshore winds, and the wave quality is consistently described as marginal or poor. It’s a tough stretch.
We start Monday 20 July with some clouds and a moderate breeze from the NE at 16 mph, with a cross-shore wind. The swell is 5 ft from the ENE, period a short 7 seconds, and combined energy at 543 (moderate). Not great. Tuesday 21 July brings rain showers and a cross-shore ENE breeze at 12 mph. Swell drops to 3 ft, but the period jumps to 15 seconds from the south, giving it a groundswell feel. Energy is 607 (moderate). Still, the wind is a problem, and the swell is small. Wednesday 22 July has a bit of a window: morning cloudy with cross-on wind, but the afternoon clears and the swell picks up to 2 ft from the SSW with a very long period of 23 seconds, energy 1128 (moderate). The wind stays cross-shore, so it’s lumpy. Thursday 23 July offers similar – small swell, long period, but the wind stays cross. Not a standout.
Friday 24 July brings a fresher breeze and a jump in swell: 7 ft to 8 ft from the ENE, period a short 7 to 8 seconds, energy hitting 1002 to 1500 (strong). This is big for the spot, but the wind is cross-shore and lumpy, and with that short period, it’s going to be a messy, chunky closeout. At over 8 ft, this is strictly for experts. Saturday 25 July sees the swell mix – 7 ft ENE in the morning (short period, energy 1395) and then a 3 ft SSW groundswell in the afternoon with an 18-second period, energy still 1395. The wind stays cross, so it’s still a messy picture.
The best chance of something decent might be Sunday 26 July. Morning has clear skies, a moderate breeze from the ENE at 12 mph, cross-shore. Swell is 4 ft from the east with a long period of 16 seconds, energy 1838 (strong). That’s a solid groundswell – the kind that can wrap into a reef well, but it can also break a bit too straight. The wind is still cross, so it’s not clean, but it’s the least choppy of the bunch. The afternoon is similar. This is the pick of the forecast, but it’s still a marginal call.
Monday 27 July to Tuesday 28 July keep the same story: east swell between 5 ft and 5 ft, periods 12 to 16 seconds, energy in the strong range, but cross-shore winds never let up. The swell direction is ENE to E, and the optimum swell direction for Ammonias is SSE, so it’s not hitting the reef perfectly. That’s a big caveat.
Wednesday 29 July has the gentlest breeze of the whole run – 9 mph from the ENE, cross-shore. Swell is 7 ft to 8 ft from the ENE, period 12 seconds, energy 1654 to 1453 (strong). That’s a lot of water, but the direction is off, and the morning is the cleaner window. For a strong surfer, this could be a big, powerful session, but it’s not the classic shape. From Thursday 30 July onward, the swell drops and the winds become more cross-onshore, with conditions deteriorating into poor, choppy surf. By the end of the first week of August, it’s all cross-onshore and small, with energies dropping to weak levels.
Overall, there’s no true standout day. Sunday 26 July and Wednesday 29 July are the closest to something rideable, but both are held back by wind and direction. If you’re desperate, keep an eye on the 29th for a bigger, more powerful wave, but it’s for experts only. Otherwise, this 16-day window is a bit of a washout for clean surf at Ammonias.
Rusty.
Short Range ForecastModerate rain (total 16mm), heaviest on Tue afternoon. Warm (max 26°C on Mon morning, min 24°C on Sun night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 9mm), mostly falling on Wed night. Warm (max 26°C on Thu afternoon, min 24°C on Wed night). Mainly fresh winds. | ||||||||||||||||||
Monday 20 | Tuesday 21 | Wednesday 22 | Thursday 23 | Friday 24 | Saturday 25 | ||||||||||||||
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 | S 15 | S 14 | S 13 | SSW 24 | SSW 23 | SSW 22 | SSW 20 | SSW 20 | SSW 18 | SSW 18 | ENE 8 | ENE 8 | ENE 8 | SSW 18 | ENE 8 |
Wave Graph | |||||||||||||||||||
204 | 220 | 207 | 217 | 275 | 320 | 285 | 437 | 564 | 480 | 528 | 399 | 543 | 415 | 644 | 555 | 604 | 731 | 605 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross | cross | cross | cross-on | cross-on | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross | cross |
High Tide | 9:50AM0.41m | 7:25PM0.35m | 11:06AM0.46m | 12:06PM0.52m | 12:55PM0.57m | 1:36PM0.61m | 00:21AM0.18m | 2:14PM0.63m | 1:16AM0.20m | ||||||||||
Low Tide | 2:18AM0.05m | 2:53PM0.29m | 2:52AM0.04m | 3:30AM0.04m | 4:16AM0.04m | 5:07AM0.04m | 10:06PM0.17m | 6:00AM0.03m | 10:10PM0.16m | ||||||||||
— | 6:03 | — | — | 6:05 | — | — | 6:05 | — | — | 6:05 | — | — | 6:05 | — | — | 6:05 | — | — | |
7:22 | — | 7:22 | — | — | 7:22 | — | — | 7:21 | — | — | 7:21 | — | — | 7:21 | — | — | 7:20 | — | |
mm | — | 1 | — | 2 | 2 | 4 | 7 | — | — | 1 | — | — | 3 | 2 | 1 | 2 | — | — | 2 |
Temp °C | 25 | 26 | 26 | 25 | 26 | 26 | 24 | 25 | 25 | 24 | 25 | 26 | 24 | 25 | 25 | 24 | 25 | 26 | 24 |
Feels °C | 24 | 25 | 24 | 24 | 26 | 26 | 24 | 24 | 23 | 23 | 24 | 25 | 23 | 24 | 24 | 22 | 24 | 25 | 22 |
Swell 1 Height (m) Direction Period (s) | SSW 11 | SSW 12 | S 16 | S 12 | S 15 | S 14 | S 13 | S 14 | S 13 | S 13 | SSW 20 | S 13 | SSW 18 | SSW 18 | SSW 17 | SSW 16 | SSW 19 | SSW 18 | SSW 18 |
73 | 104 | 188 | 110 | 275 | 320 | 285 | 311 | 280 | 212 | 528 | 219 | 469 | 356 | 428 | 302 | 502 | 731 | 547 | |
Swell 2 Height (m) Direction Period (s) | S 18 | S 16 | SSW 11 | S 15 | SSW 11 | SW 16 | SSW 26 | SSW 24 | SSW 23 | SSW 22 | S 13 | SSW 20 | S 13 | S 12 | S 12 | S 20 | SSW 16 | S 11 | E 17 |
162 | 137 | 64 | 163 | 50 | 65 | 224 | 437 | 564 | 480 | 206 | 399 | 85 | 145 | 102 | 408 | 223 | 61 | 567 | |
Swell 3 Height (m) Direction Period (s) | SE 6 | SW 18 | SW 18 | SW 16 | SW 17 | E 15 | SW 15 | E 12 | E 12 | E 12 | E 12 | E 12 | S 11 | S 22 | S 21 | S 12 | S 12 | E 18 | S 11 |
9 | 82 | 80 | 69 | 72 | 38 | 60 | 73 | 103 | 103 | 103 | 96 | 56 | 86 | 326 | 97 | 66 | 97 | 37 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | 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 8 |
204 | 220 | 207 | 217 | 210 | 200 | 220 | 212 | 181 | 232 | 307 | 227 | 543 | 415 | 644 | 555 | 604 | 506 | 605 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 16 | 16 | 31 | 16 | 31 | 31 | 38 | 33 | 16 | 16 | 31 | 31 | 16 | 31 | 31 | 16 | 16 | 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










