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Surf Forecasts:

Avellanas Rivermouth surfForecast / Guanacaste / Costa Rica

information circle12 Day Weather and Surf, issued 11 pm Thursday 12 Feb 2026 CST
Forecast update in hr  min  s Forecast update imminent
Avellanas Rivermouth surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Avellanas Rivermouth sea temperature is
26.7° C
 (Which is normal for this time of year)

Best Forecast Surf Conditions for Avellanas Rivermouth this week:

The surf forecast for Avellanas Rivermouth over the next 12 days: The first swell (rated 1 star or higher) is forecast to arrive on Saturday (Feb 14) at 3PM. The primary swell is predicted to be 0.7m and 13s period with a secondary swell of 0.4m and 9s. Another secondary swell of 0.6m and 5s is also forecast. The wind is predicted to be glassy as the swell arrives.

The most powerful waves expected at Avellanas Rivermouth in the next 12 days are 0.9m 15s and forecast to arrive on Friday (Feb 13) at 6AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 5s period and expected on Wednesday (Feb 18) at 9PM.

Wave TypeTime (CST) & Date Wave Height & Period
Next good surf (1 star+) 3PM (Sat 14th Feb)2.5ft (0.7m) 13s
Best Surf 3PM (Sat 14th Feb)2.5ft (0.7m) 13s
Most Powerful 6AM (Fri 13th Feb)3ft (0.9m) 15s

Table - best surf conditions forecast for Avellanas Rivermouth over the next 12 days.

Updates in  hr  min  s Forecast update imminent 
12 DaysHourly
Print Table

Short Range Forecast Mostly dry. Warm (max 31°C on Fri afternoon, min 23°C on Fri night). Winds decreasing (fresh winds from the ENE on Fri morning, calm by Sat afternoon).

Days 3-6 Weather Summary Mostly dry. Warm (max 31°C on Tue morning, min 23°C on Sun night). Wind will be generally light.

Friday
13
Saturday
14
Sunday
15
Monday
16
Tuesday
17
Wednesday
18
Thu
19
NightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPM
Rating
(10 max)
0
0
0
0
0
2
0
0
1
0
0
2
0
0
1
0
0
1
0
0
1
Swell
Height Map
See all maps
Wave Height (m) & direction (?)
0.7
SW
0.9
SW
0.9
SW
0.9
SW
0.7
SW
0.7
SW
0.6
SW
0.6
SW
0.4
SSW
0.5
S
0.6
SW
0.6
SW
0.5
S
0.6
SW
0.6
SW
0.5
SW
0.6
SW
0.6
S
0.4
SW
0.4
SW
0.5
SW
Period(s) (?)161414141313131216151314131313121212161615
Wave
Graph
(?)Metric surfscale
Energy kJ (?)255305305297178175138124821091381288613810473120976285104
Wind
(km/h)
30
NE
35
ENE
25
NE
25
ENE
25
ENE
0
N
15
E
15
ENE
15
WSW
5
E
10
NE
15
WSW
10
E
20
ENE
5
S
25
ENE
25
ENE
10
E
25
ENE
25
ENE
10
SSW
Wind State (?)
onshore
cross-onshore
cross-shore
cross-offshore
offshore
glassy
cross-
on		cross-
on		cross-
on		oncross-
on		glassononoffoncross-
on		cross-
off		oncross-
on		glassoncross-
on		onononcross-
off
High Tide
/ height (m)
11:54AM
1.67
12:08AM
1.96
12:54PM
1.78
1:03AM
2.05
1:43PM
1.92
1:50AM
2.16
2:24PM
2.09
2:32AM
2.26
3:02PM
2.25
3:12AM
2.35
3:38PM
2.39
3:50AM
2.40
4:15PM
2.51
Low Tide
/ height (m)
5:46AM
0.74
5:48PM
0.85
6:44AM
0.66
6:48PM
0.77
7:32AM
0.55
7:39PM
0.66
8:12AM
0.43
8:23PM
0.54
8:49AM
0.33
9:04PM
0.42
9:24AM
0.24
9:44PM
0.32
10:00AM
0.18
Friday
13
Saturday
14
Sunday
15
Monday
16
Tuesday
17
Wednesday
18
Thu
19
Sunrise-6:03--6:03--6:03--6:03--6:01--6:01--6:01-
Sunset--5:51--5:51--5:51--5:51--5:52--5:52--5:52
clear
clear
clear
clear
clear
clear
clear
part cloud
clear
clear
clear
part cloud
clear
clear
clear
clear
clear
clear
clear
clear
part cloud
Rain (mm)
---------------------
Temp. °C273031263031262928263029273131273131273129
Feels °C (?)252829233034263029293030273234283033253131
  • Map Icons:
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  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
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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.

View detailed surf forecast for Avellanas Rivermouth at:
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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 12 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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