Surf Forecasts:
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 Type | Time (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 ForecastLight 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 SummaryMostly 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 | |
Swell Height Map |  |  |  |  |  |  |  | ||||||||||||||
Wave Height (m) Direction Period (s) | SSW 6 | SSW 7 | SSW 7 | SSW 7 | S 7 | SSW 7 | S 7 | S 7 | SSW 6 | SSW 7 | SSW 6 | ESE 15 | SE 14 | SE 15 | SE 15 | SE 18 | SE 18 | SE 18 | SE 17 | SE 18 | SE 17 |
Wave Graph  | |||||||||||||||||||||
 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) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | 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 | ||||||||
 | |  |  |  |  | | |  | | | | | | |  | |  | | | | |
 | 4:47 | — | — | 4:48 | — | — | 4:48 | — | — | 4:50 | — | — | 4:50 | — | — | 4:50 | — | — | 4:52 | — | — |
 | — | 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 |
Swell 1 Height (m) Direction Period (s) | SSW 6 | SSW 7 | SSW 7 | SSW 7 | SE 10 | SSW 7 | S 7 | S 10 | SSW 6 | SSW 7 | SSW 6 | SE 5 | SE 14 | SE 15 | SE 15 | SE 18 | SE 18 | SE 18 | SE 17 | SE 18 | SE 17 |
| kJ | 43 | 38 | 29 | 16 | 4 | 15 | 24 | 2 | 13 | 9 | 14 | 3 | 54 | 110 | 181 | 522 | 686 | 1087 | 1722 | 2702 | 4541 |
Swell 2 Height (m) Direction Period (s) | SE 10 | SE 9 | SE 10 | SE 10 | SE 12 | SE 9 | SE 9 | SE 9 | SE 11 | SE 10 | SE 16 | ESE 15 | SE 5 | SSE 5 | SE 9 | SE 5 | E 14 | E 14 | — | — | — |
| kJ | 4 | 3 | 4 | 4 | 6 | 3 | 3 | 3 | 4 | 4 | 10 | 21 | 4 | 3 | 22 | 4 | 4 | 4 | — | — | — |
Swell 3 Height (m) Direction Period (s) | SE 13 | SE 12 | SE 12 | — | S 8 | SE 12 | SE 12 | S 11 | S 8 | SE 15 | SE 9 | SSW 6 | SE 9 | SE 9 | S 9 | S 8 | — | — | — | — | — |
| kJ | 6 | 6 | 6 | — | 1 | 6 | 6 | 3 | 1 | 9 | 3 | 4 | 3 | 3 | 14 | 1 | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | — | — | NNE 3 | S 7 | — | — | S 7 | — | — | SE 4 | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | 1 | 26 | — | — | 22 | — | — | 4 | — | — | — | — | — | — | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 2 | 61 | 24 | 24 | 61 | 24 | 24 | 24 | 82 | 140 | 64 | 45 | 26 | 26 | 18 | 0 | 0 | 0 | 0 | 18 | 482 |
Best forecast wave conditions in Kanagawa | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
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 Kugenuma Rivermouth 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 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.
Nearest