Nanakuli Blackrocks Surf Break

Lat Long: 21.37° N 158.14° W

Nanakuli Blackrocks Surf Forecast and Surf Report

Issued: 7 am 03 Sep 2026 (local time)

Forecast update in  hr  min

Today's Nanakuli Blackrocks sea temperature is
27.2°C
0.2° 

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


Nanakuli Blackrocks surf forecast from 3 Sep 2026:

  • Best quality surf: Monday 7 Sep, 8AM (local time) - 10ft (3.0m), 14s period, SSW swell with cross-offshore winds.
  • Most powerful swell: Monday 7 Sep, 5PM (local time) - 21ft (6.5m), 15s period, SSW swell with 18,340 kJ wave energy.
  • Next surfable swell (1★+): Saturday 5 Sep, 2AM (local time) - 3.5ft (1.1m), 11s period with S swell.

Best Forecast Surf Conditions for Nanakuli Blackrocks this week:

The surf forecast for Nanakuli Blackrocks over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Saturday (Sep 05) at 2AM. The primary swell is predicted to be 1.1m and 11s period. The wind is predicted to be offshore as the swell arrives.

The most powerful waves expected at Nanakuli Blackrocks in the next 16 days are 6.5m 15s and forecast to arrive on Monday (Sep 07) at 5PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.2m 12s period and expected on Monday (Sep 07) at 2PM.

Wave TypeTime (HST) & Date Wave Height & Period
Next good surf (1 star+) 2AM (Sat 5th Sep)3.5ft (1.1m) 11s
Best Surf 8AM (Mon 7th Sep)10ft (3.0m) 14s
Most Powerful 5PM (Mon 7th Sep)21ft (6.5m) 15s

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


The Lowdown

Alright folks, ol' Rusty here with the lowdown for the next few weeks. We're looking at a single spot, Nanakuli Blackrocks. Now, this place is a bit of a tease – it's a break that "rarely breaks" so it needs everything to line up just right. The water's sitting at a normal 81° for this time of year, so no shock there.

The first few days are a bit of a struggle. Thursday the 3rd and Friday the 4th are on the small side, with a fresh offshore breeze from the ENE keeping it clean. You're looking at waves around 2ft to 5ft from the SSE. The energy is moderate (206 to 613), but the word is "marginal" – it's rideable but not worth racing for.

Saturday the 5th is a step up. The morning sees a 5ft S swell with a moderate offshore breeze. The energy jumps to a solid 749, and the call is for "very good surf conditions". That's your first real window of opportunity.

Sunday the 6th is a standout. The morning brings a 6ft SSW swell with a gentle offshore wind from the E. The energy is strong (1610), and the report says "excellent surf conditions for experienced surfers". The period is a nice 13 seconds, so there's some proper groundswell in the water. This is a solid morning for anyone who knows what they're doing. The afternoon gets a bit messier with cross-offshore winds.

Now, Monday the 7th is a beast. We're talking a massive 13ft to 26ft S swell with a 15-second period. The energy is off the charts (5960 to 27458). But for Nanakuli Blackrocks, it's simply too big. This is strictly for the mad dogs and experts, and even then, it's a risk. The wind is a strong cross-offshore. This setup looks more interesting for the kite surfers than us paddle guys.

Things settle down after that. Sunday the 14th and Monday the 15th are your next real highlights. The morning of the 14th is tiny (1ft) and glassy with a 25-second period, but the energy is moderate (237). The afternoon is better with a 2ft SW swell, glassy, and a 23-second period pushing 528 energy. The call is "very good surf conditions". Then Tuesday the 15th morning is the pick of the second week: a 4ft SW swell, glassy, with a 21-second period and strong energy (1083). The report says "excellent conditions for experienced surfers". That's a rare, clean, long-period groundswell that will wrap in nicely.

The rest of the second week is a consistent run of clean, 3ft to 4ft SSW swells with light offshore winds, but the energy drops back into the moderate range (377 to 940). It's surfable, clean, and pleasant, but nothing to write home about.

So, the clear standouts are Sunday morning the 6th for the first week, and Tuesday morning the 15th for the second week. Both are clean, have decent energy, and are calling for excellent conditions. Just remember, Blackrocks is a rare-breaker, so when it's on, it's special, but don't bank on it.

Rusty.

Short Range Forecast

Mostly dry. Warm (max 28°C on Sat afternoon, min 25°C on Thu night). Mainly fresh winds.

Days 4-6 Weather Summary

Moderate rain (total 19mm), heaviest on Sun night. Warm (max 28°C on Mon morning, min 24°C on Sun night). Winds decreasing (strong winds from the SE on Mon night, light winds from the ESE by Tue night).

Thursday
3
Friday
4
Saturday
5
Sunday
6
Monday
7
Tuesday
8
Wednesday
9
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
1
2
1
2
2
3
3
2
3
4
4
4
!
!
0
0
2
2
2
2
2
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
0.7
S
14
1.2
SSE
12
1.1
SSE
12
1.4
SSE
12
1.4
SSE
12
1.1
S
11
1.6
S
12
1.6
S
12
1.6
SSW
12
2
SSW
12
2.3
SSW
13
2.5
SSW
14
4
SSW
15
6.5
SSW
15
3
SSW
10
1.8
S
9
1.1
SSW
14
0.9
SSW
14
0.9
SSW
14
0.9
SSW
13
0.7
SSW
13
Wave Graph
Metric surfscale
Energy kJ
206
384
306
608
579
286
723
714
794
1236
1811
2561
6144
18340
1402
498
478
356
336
257
176
Wind (km/h)
30
ENE
30
ENE
30
ENE
30
ENE
30
ENE
25
ENE
25
ENE
25
ENE
20
ENE
25
E
20
E
20
ENE
25
E
40
SE
40
S
20
S
10
S
5
ESE
5
SE
15
ENE
20
ENE
Wind State
off
off
off
off
off
off
off
off
off
off
off
off
cross-off
cross-off
cross
cross-on
cross
cross-off
glassy
off
off
High Tide
9:21AM0.60m
10:46AM0.63m
11:57AM0.67m
11:47PM0.20m
12:52PM0.70m
1:00AM0.25m
1:38PM0.72m
1:50AM0.31m
2:17PM0.71m
2:34AM0.38m
2:53PM0.68m
3:15AM0.44m
Low Tide
1:42AM0.09m
3:07AM0.10m
8:21PM0.17m
8:34PM0.14m
6:04AM0.09m
8:53PM0.12m
7:07AM0.08m
9:14PM0.10m
8:03AM0.08m
9:35PM0.09m
part cloud
clear
clear
part cloud
clear
part cloud
clear
clear
part cloud
part cloud
thunderstorm
rain showers
thunderstorm
part cloud
thunderstorm
thunderstorm
thunderstorm
clear
clear
thunderstorm
part cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
6:16
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>
6:46
6:45
6:45
6:44
6:43
6:42
6:40
 mm
2
5
1
8
2
1
1
Temp °C
27
27
25
27
27
25
27
28
26
27
27
26
28
28
27
27
28
27
28
28
26
Feels °C
25
25
22
24
24
23
26
26
26
27
28
26
28
26
23
28
30
30
32
31
26
  • Map Icons:
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  • 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 Nanakuli Blackrocks Surf forecast

The above surf forecast table for Nanakuli Blackrocks provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Nanakuli Blackrocks can be found by selecting the local surf guide option on the grey menu. Our Nanakuli Blackrocks 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 (Nanakuli Blackrocks) 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 Nanakuli Blackrocks 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.

Nanakuli Blackrocks is 6 km (4 miles) from Makakilo City. If you plan a vacation in Oahu, look for hotels and other accommodation in Makakilo City. Makakilo City has rooms for a wide range of budgets as well as car hire and transport links.

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