
Surf Forecasts:
Avellanas Rivermouth surf forecast from 28 Jul 2026:
- Best quality surf: Tuesday 28 Jul, 12PM (local time) - 5.5ft (1.7m), 17s period, SW swell with cross-offshore winds.
- Most powerful swell: Tuesday 28 Jul, 12PM (local time) - 5.5ft (1.7m), 17s period, SW swell with 1,722 kJ wave energy.
- Next surfable swell (1★+): Tuesday 28 Jul, 12PM (local time) - 5.5ft (1.7m), 17s period with SW swell.
Best Forecast Surf Conditions for Avellanas Rivermouth this week:
The surf forecast for Avellanas Rivermouth over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Jul 28) at 12PM. The primary swell is predicted to be 1.7m and 17s period with a secondary swell of 0.4m and 9s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Avellanas Rivermouth in the next 16 days are 1.7m 17s and forecast to arrive on Tuesday (Jul 28) at 12PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 4s period and expected on Saturday (Aug 01) at 6PM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12PM (Tue 28th Jul) | 5.5ft (1.7m) 17s |
| Best Surf | 12PM (Tue 28th Jul) | 5.5ft (1.7m) 17s |
| Most Powerful | 12PM (Tue 28th Jul) | 5.5ft (1.7m) 17s |
Table - best surf conditions forecast for Avellanas Rivermouth over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what’s shaping up for the next couple of weeks.
We’ve got a solid pulse of groundswell rolling in at Avellanas Rivermouth, but it’s a bit of a mixed bag with the wind. The water is a touch warmer than normal for this time of year, sitting at 86°F, which is a nice bonus.
The standout window is Tuesday, July 28th. The morning starts with a 6 ft swell from the SW, with a very long period of 18 seconds – that’s proper groundswell energy. The combined energy is a strong 1826, so there’s plenty of push. The wind is a light cross-on from the ENE at 6 mph, which is manageable. But the real magic happens in the afternoon: the wind swings to a cross-offshore from the SW at 9 mph, cleaning it right up. The swell stays at 6 ft with a 17-second period, and the energy is 1733. This is excellent for experienced surfers – the rivermouth will be handling that long-period swell beautifully. Crowds are likely here, so get your timing right.
Wednesday, July 29th, is also a good call. The swell drops a touch to 5 ft, still with a long 16-second period from the SW. The afternoon session looks best again, with that cross-off SW wind at 9 mph keeping things clean (energy 1205). The mornings are a bit choppy with a cross-on NE breeze.
After that, the swell fades. Thursday, July 30th, sees the morning wrecked by a 16 mph ENE cross-on wind, making it a write-off. The afternoon is cleaner with a 4 ft SW swell and light cross-off wind, but it’s much smaller. By Friday, July 31st, the swell drops to 3 ft, and the weekend is small – 3 ft on Saturday and 2 ft by Sunday. The only bright spot there is Sunday, August 2nd, morning: a glassy 2 ft swell with a 15-second period and light ESE wind. It’s clean but tiny, so only for the longboard or a fun fish.
The first week of August looks pretty flat. We’ve got a gap of several days here with no real recommendations. The swell struggles to get above 3 ft, and mornings are mostly blown out by strong ENE winds. The afternoons are often clean but the waves are small and weak. The combined energy drops into the low hundreds, showing a real lack of punch.
There is a flicker of hope on Saturday, August 8th, in the afternoon. The swell builds to 3 ft from the SW with a 15-second period, and the wind goes completely glassy – calm at 0 mph. The energy is 549, which is moderate. It’s the cleanest option in that second week, but it’s a long way out, so keep an eye on it.
Tuesday, August 12th, sees a new pulse of SW swell arriving with an 18-second period and 3 ft height. The afternoon has a cross-off wind, but the energy is a solid 880. It’s promising, but it’s more than a week away, so don’t lock it in yet.
Overall, hit Tuesday afternoon, July 28th, and Wednesday afternoon, July 29th, for the best waves. The rest of the run is a waiting game.
Rusty.
Short Range ForecastMostly dry. Warm (max 33°C on Thu morning, min 25°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 26mm), heaviest during Sun afternoon. Warm (max 31°C on Sat morning, min 26°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Tuesday 28 | Wednesday 29 | Thursday 30 | Friday 31 | Saturday 1 | Sunday 2 | Monday 3 | |||||||||||||||
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) | SW 18 | SW 17 | SW 16 | SW 16 | SW 16 | SW 15 | SW 14 | SW 14 | SW 14 | SW 14 | SW 13 | SW 13 | SW 13 | SW 13 | SW 12 | SW 15 | SW 15 | SW 14 | SW 14 | SW 13 | SSW 13 |
Wave Graph | |||||||||||||||||||||
1741 | 1682 | 1456 | 1194 | 1149 | 856 | 667 | 589 | 485 | 357 | 342 | 326 | 238 | 234 | 147 | 134 | 171 | 167 | 228 | 208 | 111 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-off | glassy | cross-on | cross-off | cross-on | cross-on | cross-off | on | cross-on | cross-off | on | cross-on | cross-off | on | glassy | cross-off | glassy | on | cross-off | glassy |
High Tide | 1:59PM2.16m | 2:35AM2.01m | 2:41PM2.23m | 3:15AM2.12m | 3:20PM2.28m | 3:52AM2.22m | 3:58PM2.30m | 4:27AM2.30m | 4:35PM2.29m | 5:02AM2.35m | 5:11PM2.26m | 5:37AM2.38m | 5:50PM2.20m | ||||||||
Low Tide | 8:25PM0.43m | 8:31AM0.59m | 9:03PM0.35m | 9:13AM0.53m | 9:38PM0.31m | 9:52AM0.48m | 10:12PM0.28m | 10:30AM0.44m | 10:46PM0.28m | 11:08AM0.42m | 11:19PM0.30m | 11:47AM0.42m | 11:55PM0.34m | ||||||||
5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | |
— | 6:07 | — | — | 6:07 | — | — | 6:07 | — | — | 6:06 | — | — | 6:06 | — | — | 6:06 | — | — | 6:06 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | 3 | — | 3 | 4 | — | 15 | 1 | — | 3 | 2 |
Temp °C | 31 | 29 | 27 | 31 | 29 | 27 | 33 | 30 | 28 | 30 | 29 | 28 | 31 | 29 | 27 | 31 | 28 | 27 | 30 | 29 | 28 |
Feels °C | 34 | 31 | 31 | 34 | 32 | 30 | 35 | 33 | 31 | 32 | 31 | 32 | 34 | 32 | 31 | 35 | 31 | 32 | 33 | 32 | 32 |
Swell 1 Height (m) Direction Period (s) | SW 18 | SW 17 | SW 16 | SW 16 | SW 16 | SW 15 | SW 14 | SW 14 | SW 14 | SW 14 | SW 13 | SW 13 | SW 13 | SW 13 | SW 12 | SW 12 | S 7 | S 7 | SW 14 | SW 13 | S 7 |
1741 | 1682 | 1456 | 1194 | 1149 | 856 | 667 | 589 | 485 | 357 | 342 | 326 | 238 | 234 | 147 | 108 | 49 | 52 | 228 | 208 | 48 | |
Swell 2 Height (m) Direction Period (s) | S 11 | SSW 9 | S 11 | S 11 | S 10 | S 7 | S 7 | NNW 10 | S 6 | S 7 | S 7 | S 7 | S 12 | SW 16 | SW 16 | S 7 | SW 15 | SW 12 | S 7 | S 7 | SSW 13 |
60 | 26 | 61 | 56 | 56 | 23 | 24 | 19 | 12 | 15 | 16 | 17 | 72 | 66 | 124 | 33 | 171 | 118 | 47 | 34 | 111 | |
Swell 3 Height (m) Direction Period (s) | SSW 11 | SSW 11 | — | SSW 11 | — | — | W 13 | W 12 | WNW 11 | WNW 11 | WNW 12 | WNW 11 | WNW 11 | S 7 | S 7 | SW 15 | SSW 11 | SW 14 | WSW 13 | WNW 10 | SW 13 |
25 | 25 | — | 38 | — | — | 4 | 11 | 24 | 25 | 27 | 40 | 22 | 17 | 15 | 134 | 85 | 167 | 69 | 36 | 84 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | NNW 10 | — | NNE 4 | NNE 5 | — | — | NNE 4 | N 4 | NNE 4 | N 4 | — | — | — | — | — |
— | — | — | — | — | — | 34 | — | 7 | 9 | — | — | 3 | 5 | 11 | 3 | — | — | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1 | 0 | 0 | 1 | 0 | 1 | 7 | 0 | 1 | 1 | 68 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 |
Best forecast wave conditions in Guanacaste | |||||||||||||||||||||
Best forecast wave conditions in Costa Rica | |||||||||||||||||||||
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Information about the Avellanas Rivermouth Surf forecast
The above surf forecast table for Avellanas Rivermouth provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Avellanas Rivermouth can be found by selecting the local surf guide option on the grey menu. Our Avellanas 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 (Avellanas 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 Avellanas 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.
Avellanas Rivermouth is 44 km (27 miles) from Nicoya. If you plan a holiday in Guanacaste, look for hotels and other accommodation in Nicoya. Nicoya has rooms for a wide range of budgets as well as car hire and transport links.










