Surf Forecasts:
Avellanas Rivermouth surf forecast from 15 Oct 2026:
- Best quality surf: Sunday 18 Oct, 12PM (local time) - 4.5ft (1.4m), 16s period, SW swell with glassy winds.
- Most powerful swell: Sunday 18 Oct, 3PM (local time) - 4.5ft (1.4m), 16s period, SW swell with 1,031 kJ wave energy.
- Next surfable swell (1★+): Thursday 15 Oct, 9PM (local time) - 3ft (0.9m), 14s period with SSW 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 Thursday (Oct 15) at 9PM. The primary swell is predicted to be 0.9m and 14s period with a secondary swell of 0.5m and 7s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Avellanas Rivermouth in the next 16 days are 1.4m 16s and forecast to arrive on Sunday (Oct 18) at 3PM. Winds are predicted to be cross-offshore at the time the swell arrives.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Thu 15th Oct) | 3ft (0.9m) 14s |
| Best Surf | 12PM (Sun 18th Oct) | 4.5ft (1.4m) 16s |
| Most Powerful | 3PM (Sun 18th Oct) | 4.5ft (1.4m) 16s |
Table - best surf conditions forecast for Avellanas Rivermouth over the next 16 days.
Short Range ForecastHeavy rain (total 31mm), heaviest during Thu afternoon. Warm (max 29°C on Thu morning, min 26°C on Thu night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 29mm), heaviest during Sun night. Warm (max 29°C on Sun morning, min 24°C on Sun night). Wind will be generally light. | ||||||||||||||||||||
Thursday 15 | Friday 16 | Saturday 17 | Sunday 18 | Monday 19 | Tuesday 20 | Wednesday 21 | |||||||||||||||
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 14 | SW 14 | SSW 14 | SW 19 | SW 18 | SW 18 | SW 17 | SW 16 | SW 16 | SW 16 | SW 16 | SW 16 | SW 15 | SW 15 | SW 14 | SW 15 | SW 14 | SW 14 | SW 14 | SW 14 | SSW 18 |
Wave Graph  | |||||||||||||||||||||
 kJ | 476 | 401 | 328 | 450 | 649 | 799 | 834 | 786 | 964 | 929 | 1031 | 883 | 631 | 623 | 536 | 543 | 476 | 476 | 395 | 390 | 541 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | cross | on | glassy | cross-off | cross-on | cross-on | off | on | cross-on | cross-off | on | glassy | glassy | on | on | off | on | on | cross-off | cross-on |
High Tide | 5:40PM2.09m | 5:50AM2.21m | 6:22PM1.98m | 6:33AM2.08m | 7:08PM1.87m | 7:20AM1.96m | 8:03PM1.79m | 8:16AM1.86m | 9:06PM1.77m | 9:21AM1.81m | 10:11PM1.81m | 10:29AM1.82m | 11:09PM1.92m | ||||||||
Low Tide | 11:32AM0.32m | 11:39PM0.52m | 12:12PM0.44m | 00:20AM0.64m | 12:56PM0.56m | 1:07AM0.76m | 1:46PM0.67m | 2:03AM0.86m | 2:44PM0.75m | 3:11AM0.91m | 3:47PM0.78m | 4:22AM0.88m | 4:47PM0.75m | ||||||||
 | |  | | | |  | | | |  |  |  | | | | | |  | |  | |
 | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — |
 | — | 5:25 | — | — | 5:24 | — | — | 5:24 | — | — | 5:23 | — | — | 5:23 | — | — | 5:22 | — | — | 5:22 | — |
mm | 1 | 6 | 6 | 1 | 2 | 5 | 1 | 4 | 5 | 3 | 6 | 6 | — | 3 | 4 | — | 2 | 5 | — | — | — |
Temp °C | 29 | 29 | 27 | 29 | 29 | 27 | 29 | 29 | 28 | 29 | 28 | 25 | 29 | 29 | 27 | 29 | 28 | 26 | 29 | 28 | 27 |
Feels °C | 33 | 33 | 31 | 33 | 33 | 31 | 33 | 33 | 32 | 33 | 31 | 27 | 33 | 34 | 31 | 33 | 31 | 29 | 33 | 31 | 31 |
Swell 1 Height (m) Direction Period (s) | SW 14 | SW 14 | SSW 14 | SW 13 | SW 18 | SW 18 | SW 17 | SW 16 | SW 16 | SW 16 | SW 16 | SW 16 | SW 15 | SW 15 | SW 14 | SW 15 | SW 14 | SW 14 | SW 14 | SW 14 | S 8 |
| kJ | 476 | 401 | 328 | 257 | 649 | 799 | 834 | 786 | 964 | 929 | 1031 | 883 | 631 | 623 | 536 | 543 | 476 | 476 | 395 | 390 | 121 |
Swell 2 Height (m) Direction Period (s) | S 7 | S 7 | SW 20 | SW 19 | SW 13 | SW 13 | SW 13 | SSW 12 | S 7 | S 7 | S 7 | WNW 12 | WNW 11 | WNW 12 | WNW 11 | S 8 | S 8 | S 7 | S 7 | S 7 | SSW 14 |
| kJ | 33 | 37 | 312 | 450 | 253 | 175 | 132 | 101 | 32 | 37 | 49 | 161 | 148 | 158 | 109 | 42 | 40 | 37 | 48 | 46 | 323 |
Swell 3 Height (m) Direction Period (s) | WNW 10 | NW 11 | S 7 | S 7 | S 7 | S 7 | S 6 | S 6 | W 7 | W 12 | WNW 11 | S 7 | S 7 | S 8 | S 8 | WNW 11 | WNW 10 | WNW 10 | SSW 19 | SSW 18 | SSW 18 |
| kJ | 33 | 29 | 25 | 24 | 17 | 23 | 21 | 20 | 8 | 78 | 95 | 43 | 38 | 28 | 43 | 66 | 59 | 56 | 251 | 292 | 541 |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 1 | 25 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | 1 |
Best forecast wave conditions in Guanacaste | |||||||||||||||||||||
Best forecast wave conditions in Costa Rica | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Avellanas 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 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.
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