Ammonias Surf Break

Lat Long: 21.95° N 159.35° W

Ammonias Surf Forecast and Surf Report

Issued: 1 am 17 Aug 2026 (local time)

Forecast update in  hr  min

Today's Ammonias sea temperature is
26.6° C
0.2° 

Ammonias surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.


Ammonias surf forecast from 17 Aug 2026:

  • Best quality surf: Saturday 22 Aug, 2AM (local time) - 2.5ft (0.8m), 16s period, SSW swell with cross-offshore winds.
  • Most powerful swell: Monday 17 Aug, 2PM (local time) - 6ft (1.8m), 8s period, ENE swell with 358 kJ wave energy.
  • Next surfable swell (1★+): Thursday 20 Aug, 11PM (local time) - 2.5ft (0.7m), 16s period with SW 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 (Aug 20) at 11PM. The primary swell is predicted to be 0.7m and 16s period. 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 1.8m 8s and forecast to arrive on Monday (Aug 17) 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 0.9m 6s period and expected on Thursday (Aug 20) at 8AM.

Wave TypeTime (HST) & Date Wave Height & Period
Next good surf (1 star+)11PM (Thu 20th Aug)2.5ft (0.7m) 16s
Best Surf 2AM (Sat 22nd Aug)2.5ft (0.8m) 16s
Most Powerful 2PM (Mon 17th Aug)6ft (1.8m) 8s

Table - best surf conditions forecast for Ammonias over the next 16 days.


The Lowdown

Alright, Rusty here. Let’s talk about what’s on the table for Ammonias over this 16-day stretch. I’ll level with you straight up: it’s a tough outlook. The whole period is filled with poor surf conditions and only a handful of days that even reach “marginal.” There's no standout session that I’d get properly excited about.

The first real window of surf we can talk about starts on the 20th of August. Thursday afternoon sees a little pulse of swell—only 2ft from the SSW with a long period of 17 seconds, which gives it some shape. Winds are light cross-shore from the NE at 15 km/h, so it’s not all messy. The combined energy is weak at 225, so it’s more of a longboard or a sneaky session if you’re desperate. The break itself is a reef, fairly consistent, and likes an offshore from the NW. We’re not getting that, so it’ll be a bit average.

From the 24th of August through to the 27th, there’s a build in swell. Monday the 24th morning sees 6ft from the ENE with a short 7-second period—so it’s lumpy, not groundswell. Winds are cross-shore at 12 mph, keeping it rough. Combined energy hits moderate levels (613). It’s rated marginal. Nothing to write home about. The 25th and 27th see similar conditions, with swell nudging 7ft to 8ft, still short period, still cross-shore winds. That 8ft is getting into the “not for beginners” territory, but the chop will make it ugly for everyone.

Now, the end of August throws up some bigger numbers, but don’t let the size fool you. On Friday the 28th afternoon, we’ve got 12ft of ENE swell at 11 seconds—that’s a proper swell height, long period, and strong wave energy (3081). The trouble? It’s cross-shore wind at 12 mph, so it’ll be a washing machine. That size is expert-only, and even then, the conditions will be rough. The break is a reef, so the longer period (11 seconds) should wrap in nicely, but the chop will ruin the takeoff. Saturday the 29th morning is similar—10ft and onshore—making it a total mess. I’d say this setup looks more interesting for a kite surfer than a paddle surfer.

We have a quiet end to the run. The 30th and 31st of August drop right back to 2ft with long SSW swell (16 seconds), but cross-shore winds keep it from cleaning up. Weak energy (362). By the 1st of September, Tuesday morning, we get a 7ft pulse from the E at 9 seconds, but it’s cross-onshore and choppy again. The whole 16 days is a struggle. If you’re set on paddling out, the 27th of August Thursday afternoon might be your best bet: 8ft ENE at 8 seconds, cross-shore with a gentle breeze, combined energy of 1292 (moderate). It’s marginal, but with a little luck and a forgiving tide, you might find a few.

There’s no true standout. I wouldn’t plan a trip around this. The water temperature is about average for the time of year, so no shock there. Crowds are “often” at this reef, so you might have company, but on days like this, I doubt many will show.

Stay patient. It tends not to stay this poor for long.

Rusty.

Short Range Forecast

Light rain (total 6mm), mostly falling on Mon morning. Warm (max 26°C on Mon morning, min 24°C on Mon night). Wind will be generally light.

Days 4-6 Weather Summary

Mostly dry. Warm (max 27°C on Fri afternoon, min 24°C on Thu morning). Wind will be generally light.

Monday
17
Tuesday
18
Wednesday
19
Thursday
20
Friday
21
Saturday
22
Sunday
23
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
0
0
1
0
0
0
0
0
1
1
0
2
1
0
3
0
0
1
0
1
1
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
1.7
ENE
8
1.8
ENE
7
0.8
S
14
1.4
ENE
7
0.7
S
13
1.3
ENE
7
1.2
ENE
7
1.1
ENE
6
0.5
SW
16
0.6
SSW
18
0.6
SSW
17
0.7
SW
16
0.7
SSW
17
0.7
SW
16
0.8
SSW
16
0.7
SW
16
0.7
SW
16
0.7
SSW
16
1.6
ENE
7
1.8
ENE
7
1.8
ENE
7
Wave Graph
Metric surfscale
Energy kJ
348
349
247
165
165
141
129
93
130
207
195
278
255
258
322
261
251
219
269
276
293
Wind (km/h)
25
E
20
ENE
20
ENE
20
E
20
ENE
20
ENE
20
ENE
15
ENE
15
ENE
15
ENE
15
ENE
10
NNE
10
ESE
10
ESE
5
NNE
15
ENE
15
ENE
20
ENE
20
ENE
25
ENE
20
ENE
Wind State
cross-on
cross-on
cross
cross-on
cross
cross-on
cross-on
cross
cross
cross
cross
cross-off
cross-on
cross-on
cross-off
cross-on
cross-on
cross
cross-on
cross
cross
High Tide
6:01PM0.36m
8:46AM0.48m
5:31PM0.30m
10:06AM0.50m
11:20AM0.53m
12:20PM0.56m
11:30PM0.20m
1:07PM0.59m
00:35AM0.22m
1:46PM0.62m
1:16AM0.25m
Low Tide
1:11PM0.26m
00:55AM0.06m
3:13PM0.30m
1:28AM0.08m
2:14AM0.09m
3:21AM0.10m
9:24PM0.19m
9:13PM0.18m
5:45AM0.08m
9:16PM0.18m
thunderstorm
thunderstorm
part cloud
part cloud
part cloud
part cloud
part cloud
part cloud
part cloud
part cloud
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
part cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
6:15
6:16
6:16
6:16
6:16
6:16
6:16
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
7:06
7:06
7:05
7:04
7:02
7:01
7:01
 mm
3
3
Temp °C
26
26
25
26
26
25
25
26
24
26
26
25
26
27
26
27
27
26
26
27
25
Feels °C
28
27
26
27
26
25
26
26
25
27
27
27
29
30
29
29
28
28
27
28
25
  • Map Icons:
  • Break
  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
Map placeholder
How to use the Wavefinder 
submit an eyeball surf report

Quick surf report for Ammonias:

join our community of surf reporters

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 locationNearest