
Surf Forecasts:
Kugenuma Rivermouth surf forecast from 6 Aug 2026:
- Best quality surf: Friday 7 Aug, 3AM (local time) - 6ft (1.8m), 13s period, S swell with glassy winds.
- Most powerful swell: Thursday 6 Aug, 9PM (local time) - 6ft (1.9m), 14s period, S swell with 1,352 kJ wave energy.
- Next surfable swell (1★+): Friday 7 Aug, 3AM (local time) - 6ft (1.8m), 13s period with S 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 Friday (Aug 07) at 3AM. The primary swell is predicted to be 1.8m and 13s period with a secondary swell of 0.8m and 10s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Kugenuma Rivermouth in the next 16 days are 1.9m 14s and forecast to arrive on Thursday (Aug 06) at 9PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 3s period and expected on Tuesday (Aug 11) at 9PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 3AM (Fri 7th Aug) | 6ft (1.8m) 13s |
| Best Surf | 3AM (Fri 7th Aug) | 6ft (1.8m) 13s |
| Most Powerful | 9PM (Thu 6th Aug) | 6ft (1.9m) 14s |
Table - best surf conditions forecast for Kugenuma Rivermouth over the next 16 days.
The Lowdown
G’day, I’m Rusty. Let’s have a look at what’s coming up for Kugenuma Rivermouth.
Right off the bat, we’ve got a bit of a slow start, but it’s the first real pulse of the forecast period. Thursday morning, 6th August is the pick of the whole two weeks, so don’t sleep on it. We’re looking at a solid 6 ft swell from the SSE, with a 13-second period. That’s a proper groundswell with some real push behind it—the combined energy is right up there at 1131 (moderate wave energy). The wind is a cross-off from the NE at 9 mph, keeping things clean. It’s a river mouth break, so it’s exposed and handles that S direction well. The water is sitting at 82°, a touch warmer than normal for this time of year. The swell is 6 ft, so it’s a bit meaty for beginners, but it’s not a beast. Crowds are often here, so expect company. That Thursday morning is the standout.
After that, the surf drops away fast. That 6 ft swell drops to 5 ft on Friday morning, but the wind swings cross-on from the SSE, so it’s messy. The combined energy drops to 974 (moderate). By Friday afternoon it’s onshore and rubbish. The weekend gets smaller and weaker, and by Sunday the swell is down to 2 ft, with poor conditions. From Monday 10th August through to the end of the first week, we’re in the doldrums. Swell heights hover around 2 ft to 1 ft, with combined energy values dropping to two digits (weak wave energy). There are occasional offshore or cross-off winds, but the waves are tiny and ordinary. Even the Wednesday 12th has a bit of a cross-off, but the swell is only 2 ft. It’s a real flat spell.
The second week doesn’t offer much hope either. From 13th to 17th August, it’s mostly 1.0 ft to 1 ft swell, with a few days of clean offshore winds, but the energy is just too low. The combined energy is often under 50 (weak wave energy). There’s a little bump on the 18th, with a 1 ft swell from the SE, period 12 seconds, and a clean cross-off, but it’s still tiny. By the 19th and 20th, the swell tries to pick up to 2 ft, with a 15-second period on the 19th morning—very long period, but only 1.0 ft of height. That’s a lot of period with no power. The 20th Thursday afternoon has a gentle offshore from the NE, and the swell is 2 ft from the S with a 12-second period, combined energy 93 (weak). It’s surfable but very ordinary. The 21st Friday has a similar story: 2 ft from the S, 12-second period, light cross-off wind, and energy of 111 (weak). It’s the best of a bad bunch in the second week, but it’s still a long way off and not exactly firing.
Honestly, if you’re keen, get out there Thursday morning 6th August. After that, it’s a long wait for anything worth paddling for. The setup looks more interesting for kite surfing than paddle surfing for most of this period.
Rusty.
Short Range ForecastMostly dry. Warm (max 29°C on Thu afternoon, min 25°C on Sat night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 30°C on Mon afternoon, min 24°C on Tue night). Winds decreasing (fresh winds from the N on Mon night, calm by Tue night). | |||||||||||||||||||
Thu 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | ||||||||||||||
PM | 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) | S 13 | S 14 | S 13 | S 12 | S 11 | S 11 | S 11 | SSW 11 | S 10 | S 11 | S 10 | SSW 11 | SSW 11 | SSW 10 | SSW 11 | SSW 11 | SSW 11 | SSW 11 | SSW 11 | SW 11 |
Wave Graph | ||||||||||||||||||||
1053 | 1294 | 810 | 625 | 426 | 302 | 247 | 198 | 102 | 82 | 78 | 93 | 88 | 62 | 70 | 69 | 71 | 70 | 47 | 21 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | on | cross-on | cross-on | on | on | cross-off | on | cross-off | cross-off | cross-off | off | off | cross-off | cross-off | cross | on | off |
High Tide | 9:37PM1.40m | 10:28PM1.35m | 5:09PM1.29m | 11:56PM1.32m | 5:08PM1.37m | 1:34AM1.33m | 5:20PM1.42m | 2:44AM1.38m | 5:32PM1.44m | 3:36AM1.44m | 5:45PM1.45m | |||||||||
Low Tide | 6:19AM0.48m | 7:46AM0.40m | 8:22PM1.25m | 8:49AM0.30m | 9:37PM1.20m | 9:36AM0.23m | 10:13PM1.12m | 10:14AM0.18m | 10:39PM1.03m | 10:47AM0.17m | 11:02PM0.93m | |||||||||
— | — | 4:54 | — | — | 4:54 | — | — | 4:56 | — | — | 4:56 | — | — | 4:56 | — | — | 4:58 | — | — | |
6:40 | — | — | 6:39 | — | — | 6:38 | — | — | 6:37 | — | — | 6:37 | — | — | 6:36 | — | — | 6:35 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 7 |
Temp °C | 29 | 27 | 28 | 28 | 27 | 28 | 28 | 26 | 28 | 29 | 27 | 29 | 30 | 26 | 28 | 29 | 25 | 27 | 28 | 26 |
Feels °C | 32 | 31 | 30 | 29 | 30 | 30 | 29 | 28 | 31 | 29 | 29 | 27 | 29 | 24 | 26 | 27 | 23 | 29 | 29 | 29 |
Swell 1 Height (m) Direction Period (s) | S 13 | S 14 | S 13 | S 12 | S 11 | S 11 | S 11 | SSW 11 | S 10 | S 11 | S 10 | SSW 11 | SSW 11 | SSW 10 | SSW 11 | SSW 11 | SSW 11 | SSW 11 | SSW 11 | SSW 10 |
1053 | 1294 | 810 | 625 | 426 | 302 | 247 | 198 | 102 | 82 | 78 | 93 | 88 | 62 | 70 | 69 | 71 | 70 | 47 | 21 | |
Swell 2 Height (m) Direction Period (s) | ESE 11 | ESE 10 | ESE 9 | SE 9 | SE 12 | ESE 11 | ESE 12 | ESE 12 | ESE 13 | ESE 13 | ESE 12 | ESE 12 | ESE 11 | ESE 11 | SW 12 | SE 13 | SE 13 | SE 12 | ESE 11 | SW 11 |
11 | 114 | 148 | 192 | 6 | 11 | 13 | 30 | 34 | 34 | 15 | 14 | 12 | 12 | 6 | 6 | 7 | 5 | 11 | 20 | |
Swell 3 Height (m) Direction Period (s) | — | — | E 15 | SE 9 | E 15 | SE 12 | SE 12 | SE 12 | SW 12 | SW 12 | SW 12 | SE 11 | SE 11 | SE 14 | SE 12 | SW 12 | E 10 | S 10 | S 10 | ESE 11 |
— | — | 4 | 21 | 4 | 6 | 6 | 5 | 21 | 6 | 23 | 4 | 5 | 7 | 6 | 6 | 2 | 2 | 2 | 11 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | S 2 | — | — | — | — | — | — | NE 2 | NNE 3 | ENE 3 | NE 3 | NE 3 | NE 3 | NE 3 |
— | — | — | — | — | — | 1 | — | — | — | — | — | — | 1 | 3 | 4 | 5 | 3 | 2 | 5 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 45 | 7 | 64 | 64 | 64 | 13 | 49 | 7 | 0 | 49 | 0 | 8 | 18 | 30 | 140 | 463 | 0 | 8 | 57 | 8 |
Best forecast wave conditions in Kanagawa | ||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||
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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.











