Surf Forecasts:
Mainside surf forecast from 6 Aug 2026:
- Best quality surf: Friday 7 Aug, 12PM (local time) - 26ft (8.0m), 11s period, NNW swell with onshore winds.
- Most powerful swell: Friday 7 Aug, 6PM (local time) - 26ft (8.0m), 11s period, WNW swell with 16,135 kJ wave energy.
- Next surfable swell (1★+): Friday 7 Aug, 12PM (local time) - 26ft (8.0m), 11s period with NNW swell.
Best Forecast Surf Conditions for Mainside this week:
The surf forecast for Mainside over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Friday (Aug 07) at 12PM. The primary swell is predicted to be 8.0m and 11s period with a secondary swell of 1.9m and 16s. Another secondary swell of 2.1m and 12s is also forecast. The wind is predicted to be onshore as the swell arrives.
The most powerful waves expected at Mainside in the next 16 days are 8.0m 11s and forecast to arrive on Friday (Aug 07) at 6PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 8.5m 11s period and expected on Friday (Aug 07) at 9PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12PM (Fri 7th Aug) | 26ft (8.0m) 11s |
| Best Surf | 12PM (Fri 7th Aug) | 26ft (8.0m) 11s |
| Most Powerful | 6PM (Fri 7th Aug) | 26ft (8.0m) 11s |
Table - best surf conditions forecast for Mainside over the next 16 days.
The Lowdown
Alright, let’s break it down, imperial style. Mainside is lookin’ at a rough couple weeks ahead. No sugarcoatin’ it.
Thursday the 6th is a total dud. There’s some size—about 8ft from the east—but with a strong 25 mph crosswind and messy chop, it’s not worth wettin’ a wetsuit. The water’s sittin’ at 87°, a touch warmer than usual, but that don’t help the waves.
Friday the 7th goes ballistic. A 21ft north swell rollin’ in with 11-second intervals, and the energy’s at 13,442 (very strong). Problem is, a severe gale onshore with heavy rain makes this a no-go for anyone sensible. By afternoon it’s even nastier: 26ft from the NNW with 22,284 energy (very strong) and violent storm force winds. Too big, too dangerous, even for the locals.
Saturday the 8th and Sunday the 9th flatline hard—1ft to 2ft, clean but with energy between 40 and 113 (weak to moderate). Not worth a second look.
Monday the 10th is your best shot. A 8ft west swell with a long 13-second period gives it proper push—2,076 energy (moderate). The wind is cross-off and clean. A reef like this can handle that west swell if the angle’s right. It’s marginal on the tide, but for an advanced surfer, Monday mornin’ could serve up some meaty, lined-up sets. Keep an eye out for a few others in the water though.
Then it’s back to the doldrums. Tuesday the 11th through the 20th is mostly tiny—1.0ft to 4ft—with marginal or poor conditions. Wednesday the 19th afternoon stands out a little: 4ft east swell, 9-second period, 203 energy (moderate), and offshore wind. Could be a fun small-wave cruise on a longboard.
Thursday the 20th morning has a similar 4ft east swell with 283 energy (moderate) and cross-off breeze—again, borderline but worth a peek if you’re keen.
From the 20th onward it fades to nothin’ by the 21st.
So the pick of a thin bunch is Monday the 10th for the bigger, longer-period west swell, and maybe a cheeky arvo session on the 19th. Otherwise, this 16-day stretch is more about changin’ fins than rippin’ lips. Keep your ear to the ground—forecasts can flip.
Rusty.
Short Range ForecastHeavy rain (total 292mm), heaviest during Fri night. Warm (max 29°C on Thu afternoon, min 27°C on Thu night). Winds increasing (strong winds from the N on Thu afternoon, extremely windy from the WSW by Fri afternoon). | Days 5-7 Weather SummaryHeavy rain (total 28mm), heaviest during Mon night. Warm (max 30°C on Sun afternoon, min 28°C on Tue night). Winds decreasing (strong winds from the SSE on Sun afternoon, light winds from the S by Wed morning). | |||||||||||||||||||
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) | E 16 | E 16 | N 11 | WNW 10 | WNW 11 | ENE 11 | E 10 | E 10 | W 13 | W 13 | W 13 | W 12 | W 10 | W 10 | W 10 | W 9 | W 8 | W 7 | ENE 11 | ENE 10 |
Wave Graph  | ||||||||||||||||||||
 kJ | 4636 | 3916 | 8950 | 10951 | 6801 | 123 | 53 | 49 | 3369 | 2149 | 1793 | 690 | 262 | 131 | 156 | 134 | 46 | 15 | 39 | 20 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | on | on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 00:20AM1.89m | 2:33PM1.55m | 1:33AM1.83m | 4:33PM1.62m | 3:07AM1.83m | 5:46PM1.76m | 4:31AM1.92m | 6:33PM1.89m | 5:36AM2.05m | 7:10PM2.00m | 6:28AM2.16m | 7:43PM2.07m | ||||||||
Low Tide | 6:08PM1.08m | 7:37AM0.65m | 7:25PM1.25m | 9:12AM0.60m | 9:22PM1.33m | 10:37AM0.47m | 10:58PM1.26m | 11:41AM0.32m | 11:59PM1.13m | 12:31PM0.21m | 00:45AM0.97m | 1:14PM0.15m | 1:25AM0.82m | |||||||
 |  |  | | | |  | | | | |  | | | | | | | | | |
 | — | — | 5:56 | — | — | 5:56 | — | — | 5:56 | — | — | 5:58 | — | — | 5:58 | — | — | 5:58 | — | — |
 | 7:13 | — | — | 7:12 | — | — | 7:12 | — | — | 7:10 | — | — | 7:09 | — | — | 7:08 | — | — | 7:07 | — |
mm | — | 16 | 32 | 76 | 139 | 11 | 7 | 8 | 3 | 2 | 2 | — | 2 | 10 | 4 | 3 | 4 | 1 | 6 | 4 |
Temp °C | 29 | 29 | 28 | 28 | 29 | 28 | 29 | 29 | 29 | 30 | 29 | 30 | 30 | 29 | 30 | 30 | 28 | 29 | 29 | 29 |
Feels °C | 27 | 25 | 19 | 17 | 16 | 17 | 22 | 25 | 26 | 28 | 27 | 30 | 30 | 29 | 32 | 33 | 31 | 32 | 33 | 33 |
Swell 1 Height (m) Direction Period (s) | E 16 | E 16 | ENE 16 | NNE 12 | WNW 11 | ENE 11 | WSW 14 | WSW 14 | W 13 | SW 12 | W 13 | SW 12 | SW 12 | SW 12 | SW 11 | SW 11 | SW 10 | SW 9 | SW 9 | SW 9 |
| kJ | 4636 | 3916 | 4166 | 4718 | 6801 | 47 | 11349 | 7634 | 3369 | 1903 | 1793 | 1638 | 1539 | 1346 | 640 | 457 | 322 | 196 | 119 | 122 |
Swell 2 Height (m) Direction Period (s) | — | — | NNE 11 | ENE 12 | ENE 12 | ENE 11 | E 10 | E 10 | SW 11 | W 13 | E 14 | W 12 | W 10 | W 10 | S 10 | S 11 | S 9 | S 9 | S 9 | S 9 |
| kJ | — | — | 1186 | 557 | 46 | 123 | 53 | 49 | 866 | 2149 | 138 | 690 | 262 | 131 | 358 | 319 | 140 | 140 | 110 | 71 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | E 16 | — | E 15 | ENE 15 | ENE 10 | E 10 | — | E 14 | E 13 | E 13 | W 10 | W 9 | W 8 | W 7 | ENE 11 | ENE 10 |
| kJ | — | — | — | — | 5 | — | 17 | 21 | 32 | 30 | — | 184 | 171 | 115 | 156 | 134 | 46 | 15 | 39 | 20 |
Wind waves Height (m) Direction Period (s) | N 7 | N 9 | N 11 | WNW 10 | SSW 10 | SW 13 | S 11 | S 10 | S 10 | SSE 11 | SSW 12 | SSE 12 | S 11 | S 12 | — | — | — | — | SSE 2 | SE 3 |
| kJ | 392 | 2584 | 8950 | 10951 | 4686 | 23470 | 3868 | 2039 | 2186 | 1396 | 3233 | 1029 | 834 | 464 | — | — | — | — | 1 | 5 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 796 | 608 | 1330 | 758 | 622 | 758 | 622 | 622 | 618 | 618 | 600 | 600 | 600 | 600 | 622 | 608 | 600 | 600 | 14 | 14 |
Best forecast wave conditions in Okinawa | ||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||
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Information about the Mainside Surf forecast
The above surf forecast table for Mainside provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Mainside can be found by selecting the local surf guide option on the grey menu. Our Mainside 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 (Mainside) 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 Mainside 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.
Mainside is 11 km (7 miles) from the city of Ishikawa. If you plan a holiday in Okinawa, look for hotels and other accommodation in Ishikawa. Ishikawa has rooms for a wide range of budgets as well as car hire and transport links.
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