Kugenuma Rivermouth Surf Break

Lat Long: 35.31° N 139.47° E

Kugenuma Rivermouth Surf Forecast and Surf Report

Issued: 2 am 29 Jul 2026 (local time)

Forecast update in  hr  min

Today's Kugenuma Rivermouth sea temperature is
27.5° C
1.2° 

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


Kugenuma Rivermouth surf forecast from 29 Jul 2026:

  • Best quality surf: Wednesday 5 Aug, 6AM (local time) - 11ft (3.5m), 18s period, SE swell with offshore winds.
  • Most powerful swell: Wednesday 5 Aug, 9AM (local time) - 11ft (3.5m), 17s period, SSE swell with 7,266 kJ wave energy.
  • Next surfable swell (1★+): Monday 3 Aug, 3AM (local time) - 2.5ft (0.7m), 17s period with SE swell.

Best Forecast Surf Conditions for Kugenuma Rivermouth this week:

The surf forecast for Kugenuma Rivermouth over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Monday (Aug 03) at 3AM. The primary swell is predicted to be 0.7m and 17s period with a secondary swell of 0.2m and 4s. The wind is predicted to be cross-offshore as the swell arrives.

The most powerful waves expected at Kugenuma Rivermouth in the next 16 days are 3.5m 17s and forecast to arrive on Wednesday (Aug 05) at 9AM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 3s period and expected on Thursday (Jul 30) at 9AM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 3AM (Mon 3rd Aug)2.5ft (0.7m) 17s
Best Surf 6AM (Wed 5th Aug)11ft (3.5m) 18s
Most Powerful 9AM (Wed 5th Aug)11ft (3.5m) 17s

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


The Lowdown

Alright mate, let’s talk about your local stretch, Kugenuma Rivermouth. The next week and a half is proper quiet – you’ll be twiddling your thumbs for a while. The first half-decent surf doesn’t show until Monday, August 3rd. Before that, it’s mostly tiny waves with onshore or cross-shore muck. Water temp is about 82°F, which is a tad warmer than normal for this time of year, so at least it’s warm waiting.

Monday, August 3rd is when things wake up. A long-period groundswell from the SE rolls in with an 18-second period – that’s proper energy, better shape, longer lulls between sets. Morning waves around 3 feet, building to 4 feet by the afternoon, with clean offshore-ish wind from the NE. The combined swell energy gets into moderate territory (527 up to 690). That’s your standout window if you want something fun and clean without getting thumped.

Tuesday, August 4th sees the swell ramp up. Morning waves around 6 feet from the SE with a 17-second period and solid offshore NE wind at 12 mph – clean and powerful, but starting to get too big for learners. The energy is strong (1722). Afternoon bumps to nearly 7 feet, but the wind goes cross-offshore and conditions get more tricky. That’s for the experienced crew.

Wednesday, August 5th is the big daddy – a solid 12 feet of SE groundswell with a long 17-second period and strong offshore NNE wind at 19 mph. The combined energy is massive (7266). That’s huge, clean, and dangerous for this river mouth. Only experts should even think about paddling out – the long period will make it pitchy and fast.

Thursday, August 6th drops to 10 feet from the S, still solid offshore wind in the morning, but the afternoon gets sloppy with cross-shore wind and chop. The morning is the go here, but still big.

After that, the size fades. Friday and Saturday (Aug 7-8) still have some juice (5 feet down to 3 feet), but winds are messy or onshore, and quality drops. By Sunday, August 9th and into the next week, it’s back to small, weak, poor conditions – energy drops under 100. There’s a late spike on Thursday, August 13th with 8 feet SSE and strong offshore wind, but it’s a long way off and less sure.

Best bet: hit Monday, August 3rd morning for clean, fun waves that are manageable. Tuesday morning also decent for the more experienced. The rest is either too small, too big, or too blown out.

Ride the patience, mate. Rusty.

Short Range Forecast

Light rain (total 5mm), mostly falling on Thu afternoon. Warm (max 30°C on Wed afternoon, min 25°C on Fri night). Wind will be generally light.

Days 4-6 Weather Summary

Mostly dry. Warm (max 28°C on Sat afternoon, min 25°C on Sat night). Wind will be generally light.

Wednesday
29
Thursday
30
Friday
31
Saturday
1
Sunday
2
Monday
3
Tuesday
4
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
0
0
0
0
0
0
0
0
0
1
3
3
4
4
3
4
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
SSW
6
0.6
SSW
7
0.5
SSW
7
0.4
SSW
7
0.5
S
7
0.4
SSW
7
0.5
S
7
0.5
S
7
0.4
SSW
6
0.3
SSW
7
0.4
SSW
6
0.2
ESE
15
0.4
SE
14
0.5
SE
15
0.6
SE
15
0.9
SE
18
1.1
SE
18
1.3
SE
18
1.7
SE
17
2.1
SE
18
3
SE
17
Wave Graph
Metric surfscale
Energy kJ
43
38
29
16
26
15
24
22
13
9
14
21
54
110
181
522
686
1087
1722
2702
4541
Wind (km/h)
5
SSE
15
SW
15
NNE
5
NNW
10
S
0
NNW
5
ENE
5
SSE
5
S
10
E
5
S
10
SSE
10
S
15
S
10
SE
10
ENE
10
NE
10
ENE
20
NE
20
NE
25
NNE
Wind State
glassy
on
off
glassy
cross-on
glassy
glassy
cross-on
glassy
cross-off
cross-on
cross-on
cross-on
on
cross
cross-off
cross-off
cross-off
off
cross-off
off
High Tide
6:11PM1.44m
4:37AM1.50m
6:27PM1.45m
5:20AM1.52m
6:46PM1.47m
6:02AM1.50m
7:08PM1.49m
6:46AM1.45m
7:32PM1.50m
7:33AM1.36m
8:00PM1.50m
8:27AM1.25m
8:29PM1.48m
Low Tide
11:09AM0.11m
11:20PM0.96m
11:38AM0.13m
11:49PM0.86m
12:07PM0.19m
00:21AM0.76m
12:35PM0.28m
00:57AM0.67m
1:03PM0.40m
1:38AM0.60m
1:31PM0.54m
2:25AM0.56m
1:56PM0.69m
clear
clear
thunderstorm
part cloud
rain showers
rain showers
part cloud
part cloud
part cloud
part cloud
part cloud
part cloud
clear
clear
part cloud
cloud
part cloud
cloud
part cloud
clear
part cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:47
4:48
4:48
4:50
4:50
4:50
4:52
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:49
6:47
6:46
6:45
6:45
6:44
6:43
 mm
1
2
2
Temp °C
29
30
29
29
29
27
30
30
28
27
28
26
27
28
27
25
27
26
28
30
26
Feels °C
33
31
32
32
31
31
33
33
32
31
32
29
30
30
30
28
30
28
28
29
25
  • 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 Kugenuma Rivermouth Surf forecast

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

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