Umegahama Rivermouth
Pull to refresh
Hourly Forecast
Timezone: Asia/Tokyo
⏱️s.
⚡️kJ
Wednesday 03
Thursday 04
Friday 05
Saturday 06
Sunday 07
Monday 08
Tap a forecast cell to explore conditions on the map.
Surfnerd Logo
Join Surfnerd for free to check this forecast
Join Surfnerd to check forecasts, set your homespot, save and create spots and log your surf sessions.
Sign up with AppleSign up with Google

Umegahama Rivermouth surf guide

Umegahama Rivermouth is a popular surf spot known for its unique conditions. This spot works best during Southeast swells and can be a good choice for experienced surfers looking for some action. The beach is quite long, stretching up towards Shoojiun, providing a little room to explore and find your own peaks.

The waves here generally break over sand, with right-handers that can deliver quality rides, especially during mid to high tide. You can expect optimal conditions when the swell is coming from the Southeast, but it can also pick up swells from the East and South. The spot usually handles swell sizes around 2 feet (0.6 meters) quite well, but it's best suited for expert surfers due to the crowd and the nature of the waves.

Keep in mind that when the surf's on, you’ll likely be part of a crowd filled with skilled local surfers. If you want a change of scenery, you might consider making your way to Cape Toi. There, you can check out different reef breaks and enjoy the sights of the wild horses roaming around.

Surf reports and surf forecasts nearby Umegahama Rivermouth

Ikuragahama
Miyazaki, Japan
Beach break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Kisakihama
Miyazaki, Japan
Beach break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Aoshima
Miyazaki, Japan
Reef break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Uchiumi
Miyazaki, Japan
Reef break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Curren's
Miyazaki, Japan
Reef break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Chokusen
Miyazaki, Japan
Reef break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Udo Shrine
Miyazaki, Japan
Reef break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Oura
Miyazaki, Japan
Reef break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Umegahama Rivermouth
Miyazaki, Japan
Rivermouth break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Nagata
Miyazaki, Japan
Point break
Wed 3
Thu 4
Fri 5
Sat 6
Sun 7
Mon 8
Tue 9
Wed 10
Thu 11
Fri 12
Sat 13
Sun 14
Wind certainty

Wind certainty tells you how much the weather models agree on the forecast.

  • High certainty: Models agree closely; forecast is reliable.
  • Medium certainty: Some disagreement; conditions may shift slightly.
  • Low certainty: Models diverge; treat forecast with caution.

We calculate this by comparing wind speed, gust and direction from multiple models (like GFS, ECMWF, Arome, and Harmonie) and seeing how closely they match. They are weighted, meaning that some models count more than others, depending on how good they are for a certain spot.

Login to do spot actions

Readme

Welcome! If you’re new to surf forecasting, check out this quick guide.

Forecast Table

The forecast table (the section on the page with all the numbers) is designed to pack as much information in the screen as possible. Although intimidating at first, it will help you make informed decisions about the waves faster, trust me :D. The table consists of roughly four sections, time and predictions, wind, waves, and tides:

🔮 Time and predictions section

Here we show the forecast thour and the overall surf quality prediction. This is determined based on the wave, wind and tide quality prediction. These individual predictions can be found on the forecast map.

💨 Wind section

The first row on the table (with the 💨 icon) shows wind speed, direction and gust. The more the wind speed the more aggressive the color (from blue, green, orange to red).

🌊 Wave section

The waves section consists of three rows, one for wave height and direction, one for period and one for wave energy. Our algorithm choices the "dominant wave". This is normally the first swell partition, but with heavy local storms it displays the wind waves. If that's the case, we display the numbers in italic and in gray.

🌒 Tide section

The tide section consists of a row with the actual heights per hour (measured at the half hour) and a table that displays the flow of the tide and the extremes (lows and highs).

Forecast map

The forecast map consists of arrows. These arrows represent all wave partitions (swell partitions and wind wave partition) and the wind. This allows you to see things like: a secondary swell or wind waves messes up the surf, or the wind is just a tick offshore so very surfable. Click a metric label in the bottom left to bring that arrow to the front — handy when arrows overlap.

Forecast Cheat Sheet

Short on time? Focus on wave energy. It’s the best single metric to gauge how big and powerful the waves will be.

Click any table cell to jump to that forecast hour. The map will update with forecast arrows, so you can see if wind and swell direction are lining up.

Use the table sidebar to switch units for height and speed.

Log your surf sessions to compare forecasts with real sessions and sharpen future predictions.

Models and Updates

Surfnerd blends multiple global and local wind and swell models using advanced interpolation and spatial techniques to create an "ensemble" forecast. Forecasts are refreshed hourly.

Surf Predictions

Our AI-driven algorithm scores surf quality, shown by green, orange, and gray dots. Each forecast hour is rated for wind, swell, and tide quality, then combined into an overall score. Here’s the scale:

Perfect
Good
Average
Bad or No Data

Session logs also feed the algorithm — the more you log, the smarter your forecasts get.

With Surfnerd, no more "you should have been here yesterday"

Surfnerd Logo
Join Surfnerd+ and get:
  • 12-day
    forecast range
    (vs 6-day)
  • Unlimited
    spot checks
    (vs 5/day)
  • Expert AI
    surf forecast write-ups
"Great Forecasts. Nothing more, nothing less."
Surfnerd for iOS: Faster loading, smoother experience.
Download on the App Store