Ammonias Surf Break

Lat Long: 21.95° N 159.35° W

Ammonias Surf Forecast and Surf Report

Issued: 1 am 07 Aug 2026 (local time)

Forecast update in  hr  min

Today's Ammonias sea temperature is
26.6° C
0.1° 

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


Ammonias surf forecast from 7 Aug 2026:

  • Most powerful swell: Thursday 13 Aug, 2AM (local time) - 4.5ft (1.4m), 16s period, S swell with 1,029 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 Thursday (Aug 13) at 2AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 12s period and expected on Friday (Aug 14) at 2AM.

Wave TypeTime (HST) & Date Wave Height & Period
Next good surf (1 star+)--
Best Surf--
Most Powerful 2AM (Thu 13th Aug)4.5ft (1.4m) 16s

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


The Lowdown

Alright folks, Rusty here. Let’s get straight into the forecast for Ammonias.

We’re looking at a pretty long stretch of challenging conditions here. The first week is a write-off, with messy, onshore or cross-shore winds and weak, short-period swell. Things don’t start to look interesting until the second week.

Starting off, Friday the 7th and Saturday the 8th are a total loss. The wind is coming from the ENE, either cross-on or cross, and the swell is small and weak, with combined energy in the low hundreds (332 to 466). The water temp is 80°, which is perfectly normal for this time of year.

Sunday the 9th shows a slight bump in size to 5ft-6ft, but the ENE wind is still a moderate 12-16 mph and cross-shore, making it messy. The energy ticks up to around 600, but it’s still just marginal. Monday the 10th through Tuesday the 11th are in the same boat – mostly poor, with ENE cross-onshore winds and choppy conditions.

The real talking point, and the only standout in this entire 16-day window, is Wednesday the 12th through Thursday the 13th. A proper long-period S swell arrives, with periods of 15 to 18 seconds. The combined energy jumps to a strong 1000 to 1227. The swell height is modest at 3ft to 5ft, but that long period will bring some serious shape and power. Wind is still cross from the ENE, so it won’t be glassy, but it’ll be workable. For a reef break like Ammonias (exposed to SSE swells), this S swell is a near-perfect match. This is your best chance to get a wave, but keep in mind it’s a fairly consistent spot, so there will be sets.

From Friday the 14th onwards, things get messy again. The wind picks up to 19 mph, and by the 15th and 16th, the swell switches back to a short-period ENE, with heights up to 7ft. That’s a lot of bumpy, cross-chopped water. The combined energy is strong to very strong (856 to 1037), but with the wind and direction, it’s more interesting for kite surfing than paddle surfing. This messy pattern holds through the end of the window, with only marginal moments on the 21st of August.

So, short story: Tough first week, then a real window of opportunity on the 12th and 13th with a long-period south swell at Ammonias. After that, it’s back to the grind.

Rusty.

Short Range Forecast

Light rain (total 3mm), mostly falling on Sat morning. Warm (max 27°C on Sun afternoon, min 24°C on Fri night). Wind will be generally light.

Days 4-6 Weather Summary

Light rain (total 3mm), mostly falling on Mon morning. Warm (max 27°C on Tue afternoon, min 24°C on Tue night). Wind will be generally light.

Friday
7
Saturday
8
Sunday
9
Monday
10
Tuesday
11
Wednesday
12
Thursday
13
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
0
0
0
1
1
1
0
0
1
0
0
1
0
2
2
2
2
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)
0.4
SW
21
0.4
SW
20
0.4
SSW
19
1.5
ENE
6
0.5
SW
18
1.9
ENE
6
1.8
ENE
7
1.6
ENE
7
1.8
ENE
7
1.6
ENE
7
1.5
ENE
8
0.7
SSW
15
1.5
E
7
1.5
ENE
7
0.7
S
20
0.9
S
18
1.1
S
18
1.4
S
16
1.4
S
16
1.3
S
15
1.2
S
15
Wave Graph
Metric surfscale
Energy kJ
125
101
148
160
165
280
293
261
293
284
246
231
238
210
373
515
741
1029
1004
784
636
Wind (km/h)
15
ENE
20
ENE
15
NE
25
ENE
25
ENE
20
ENE
25
ENE
20
NE
20
ENE
20
ENE
20
ENE
20
ENE
20
ENE
20
ENE
20
ENE
20
ENE
25
ENE
20
ENE
20
ENE
25
ENE
25
NE
Wind State
cross-on
cross
cross
cross
cross
cross
cross
cross
cross-on
cross-on
cross
cross
cross-on
cross
cross-on
cross
cross
cross
cross
cross
cross
High Tide
12:26PM0.64m
1:18PM0.69m
00:17AM0.19m
2:05PM0.73m
1:24AM0.22m
2:47PM0.75m
2:17AM0.26m
3:26PM0.74m
3:06AM0.30m
4:02PM0.71m
3:54AM0.34m
4:34PM0.66m
4:44AM0.37m
Low Tide
4:56AM-0.01m
9:20PM0.16m
6:02AM-0.03m
9:35PM0.15m
7:01AM-0.05m
9:56PM0.13m
7:54AM-0.06m
10:20PM0.12m
8:43AM-0.04m
10:44PM0.10m
9:30AM-0.00m
11:09PM0.08m
clear
clear
part cloud
rain showers
part cloud
part cloud
part cloud
clear
rain showers
rain showers
rain showers
clear
clear
clear
part cloud
clear
clear
part cloud
part cloud
clear
part cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
6:11
6:11
6:11
6:13
6:13
6:13
6:13
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
7:13
7:13
7:12
7:10
7:10
7:09
7:08
 mm
1
2
2
1
Temp °C
26
26
25
25
26
25
26
27
25
26
26
25
26
27
25
26
26
25
27
27
25
Feels °C
27
26
25
26
25
25
26
27
25
27
27
26
26
27
25
25
25
25
26
26
25
  • Map Icons:
  • Break
  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
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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

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