Surf Forecasts:
Guiones surf forecast from 18 Aug 2026:
- Best quality surf: Tuesday 18 Aug, 3AM (local time) - 3.5ft (1.1m), 14s period, SW swell with offshore winds.
- Most powerful swell: Tuesday 18 Aug, 9PM (local time) - 3.5ft (1.1m), 16s period, SW swell with 539 kJ wave energy.
- Next surfable swell (1★+): Tuesday 18 Aug, 3AM (local time) - 3.5ft (1.1m), 14s period with SW swell.
Best Forecast Surf Conditions for Guiones this week:
The surf forecast for Guiones over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Aug 18) at 3AM. The primary swell is predicted to be 1.1m and 14s period with a secondary swell of 0.9m and 7s. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Guiones in the next 16 days are 1.1m 16s and forecast to arrive on Tuesday (Aug 18) at 9PM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 4s period and expected on Sunday (Aug 23) at 9AM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 3AM (Tue 18th Aug) | 3.5ft (1.1m) 14s |
| Best Surf | 3AM (Tue 18th Aug) | 3.5ft (1.1m) 14s |
| Most Powerful | 9PM (Tue 18th Aug) | 3.5ft (1.1m) 16s |
Table - best surf conditions forecast for Guiones over the next 16 days.
The Lowdown
Alright, Rusty here. Let's talk about what's happening at our local spot. It's a slow start, but there's some real power building for the end of the run.
Right now, the water's a warm 87°F, which is much warmer than usual for this time of year – a nice bonus. The first session that's worth getting out of bed for is on Tuesday morning, the 18th of August. We've got a 4ft SW swell with a long 14-second period, but the wind is glassy – dead calm. That means perfect, clean waves. The combined energy is moderate (530), so there's some punch there, but it's still manageable. It's a good, clean option for all levels.
After that, the waves shrink down. The rest of that week and into the next, we're looking at small stuff, 2ft or less. The mornings stay clean with glassy conditions, especially Thursday the 20th and Friday the 21st, but the energy is weak (down to 276). You could still get a longboard out there and have a little fun, but it's nothing to write home about.
Now, here's where it gets interesting. The real standout is Saturday the 29th of August and Sunday the 30th. Saturday morning is the absolute gem. We're talking a solid 5ft SW groundswell with a 17-second period and glassy conditions. That's a powerful, long-period swell, and the energy is strong (1693). This is excellent surf, but at 5ft, it's getting into the zone where it's only for experienced surfers. It's not a beginner wave. Sunday the 30th keeps that same 5ft SW swell with a 15-second period and clean offshore winds in the morning – another absolute beauty.
There are a couple of other little pulses earlier in that last week. On Monday the 24th and Tuesday the 25th of August, we get a long-period 18-second and 16-second swell, but the height is only 2ft, so the energy is weak to moderate. It'll be clean in the mornings, but it's more of a glide than a proper session. Also, on Friday the 28th of August, there's a 2ft swell with a 20-second period and clean cross-offshore winds – that long period could make it fun for the more experienced guys.
So, the bottom line: the first week is small and clean, good for a cruise. The real standouts are the Saturday 29th and Sunday 30th mornings – those are your sessions for the best waves, best winds, and the most energy. Get on it.
Rusty.
Short Range ForecastHeavy rain (total 34mm), heaviest during Mon night. Warm (max 29°C on Tue morning, min 25°C on Tue night). Wind will be generally light. | Days 5-7 Weather SummaryHeavy rain (total 24mm), heaviest during Thu afternoon. Warm (max 30°C on Sun morning, min 26°C on Thu night). Wind will be generally light. | |||||||||||||||||||
Mon 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | ||||||||||||||
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 | SW 14 | SW 14 | SW 16 | SW 15 | SW 14 | SW 14 | SW 13 | S 10 | SSW 11 | S 11 | S 11 | S 11 | S 11 | S 10 | S 10 | S 9 | SW 18 | SW 18 |
Wave Graph  | ||||||||||||||||||||
 kJ | 428 | 416 | 422 | 401 | 539 | 355 | 350 | 238 | 144 | 188 | 292 | 345 | 351 | 291 | 269 | 198 | 154 | 137 | 260 | 258 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-off | glassy | cross | off | glassy | glassy | off | glassy | cross-on | cross-off | glassy | cross-on | glassy | glassy | on | cross-off | off | cross-on | off |
High Tide | 6:00PM2.09m | 6:22AM2.21m | 6:43PM1.94m | 7:04AM2.07m | 7:29PM1.80m | 7:50AM1.94m | 8:19PM1.66m | 8:41AM1.82m | 9:19PM1.56m | 9:42AM1.74m | 10:29PM1.52m | 10:49AM1.72m | 11:39PM1.55m | |||||||
Low Tide | 00:06AM0.26m | 12:40PM0.33m | 00:48AM0.40m | 1:26PM0.45m | 1:32AM0.54m | 2:16PM0.56m | 2:21AM0.66m | 3:14PM0.64m | 3:19AM0.75m | 4:20PM0.68m | 4:28AM0.79m | 5:28PM0.66m | ||||||||
 |  |  |  | | |  |  |  | | | |  |  | | | |  | |  | |
 | — | — | 5:33 | — | — | 5:33 | — | — | 5:33 | — | — | 5:33 | — | — | 5:33 | — | — | 5:33 | — | — |
 | 5:59 | — | — | 5:59 | — | — | 5:58 | — | — | 5:58 | — | — | 5:57 | — | — | 5:57 | — | — | 5:55 | — |
mm | 4 | 6 | 4 | 8 | 11 | 1 | — | — | — | 5 | 11 | — | 1 | — | 2 | 5 | — | — | 3 | — |
Temp °C | 28 | 26 | 29 | 28 | 26 | 26 | 27 | 26 | 29 | 29 | 26 | 29 | 29 | 27 | 29 | 29 | 28 | 30 | 29 | 27 |
Feels °C | 32 | 31 | 33 | 32 | 30 | 30 | 32 | 30 | 33 | 33 | 31 | 34 | 32 | 32 | 34 | 33 | 33 | 32 | 33 | 30 |
Swell 1 Height (m) Direction Period (s) | SW 14 | SW 14 | SW 14 | SW 14 | SW 16 | SW 15 | SW 14 | S 8 | SSW 8 | S 10 | SSW 11 | S 11 | S 11 | S 11 | S 11 | S 10 | S 10 | S 9 | S 9 | S 9 |
| kJ | 428 | 416 | 422 | 401 | 539 | 355 | 350 | 113 | 118 | 188 | 292 | 345 | 351 | 291 | 269 | 198 | 154 | 137 | 106 | 109 |
Swell 2 Height (m) Direction Period (s) | S 8 | S 7 | S 8 | S 8 | S 8 | S 8 | S 8 | SW 14 | SW 13 | SW 13 | SW 13 | SW 15 | SW 15 | SW 15 | SW 14 | SW 14 | SW 13 | SW 13 | SW 18 | SW 18 |
| kJ | 115 | 88 | 100 | 98 | 95 | 89 | 90 | 238 | 144 | 140 | 83 | 76 | 75 | 183 | 95 | 158 | 84 | 85 | 260 | 258 |
Swell 3 Height (m) Direction Period (s) | S 11 | S 10 | S 10 | S 13 | S 12 | SW 6 | NW 5 | NW 8 | S 13 | S 13 | SSW 19 | SW 12 | SW 12 | SW 21 | SW 16 | SW 20 | SW 20 | SW 20 | SW 13 | SW 12 |
| kJ | 20 | 18 | 8 | 3 | 3 | 10 | 1 | 3 | 14 | 29 | 36 | 36 | 36 | 18 | 43 | 98 | 97 | 134 | 84 | 77 |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | N 4 | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 3 | — | — |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 29 | 0 | 0 | 3 | 0 | 0 | 0 | 0 | 0 | 29 | 0 | 0 | 103 | 0 | 0 | 31 | 0 | 0 | 39 | 0 |
Best forecast wave conditions in Guanacaste | ||||||||||||||||||||
Best forecast wave conditions in Costa Rica | ||||||||||||||||||||
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Information about the Guiones Surf forecast
The above surf forecast table for Guiones provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Guiones can be found by selecting the local surf guide option on the grey menu. Our Guiones 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 (Guiones) 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 Guiones 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.
Guiones is 34 km (21 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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