San Juan Surf Forecast

Tide
โฑ๏ธs.
โšก๏ธkJ
Tijdzone:
America/Puerto_Rico
Wind: SN UNITY Atmos
(20260319 09z)
Golven: SN UNITY WAVE
(20260319 09z)

Golfopbouw

Swell 1Swell 2Swell 3Wind waves

San Juan Surf Forecast Eigenschappen

Swell venster
NNW - NO
Swell hoogte
2ft - 6ft
Swell breekt over
Steen
Golftypes
Riff
Golfrichtingen
Links
Wind venster
ZO - WZW
Werkende getijden
Mid, Hoog
Niveau
Gevorderde, Expert
Seizoenen
Herfst, Winter
Boardtypes
Shortboard, Funboard, Longboard, Fish, Bodyboard

San Juan Surf Forecast Gids

San Juan is a popular surf spot located east of La Santa. Itโ€™s known for its quality left-handed waves that break over a rocky reef. When you're planning your session here, itโ€™s best to hit it at mid to high tide, making it easier to navigate around the hidden hazards that the reef presents. A big swell can make things tricky, so it's important to be prepared if you're surfing this spot.

The waves at San Juan typically range from chest high to overhead (roughly 1 to 2 meters). The best swell directions are from the North, North Northwest, and North Northeast, handling sizes from about 1 meter (3 ft) up to 2 meters (6 ft). The spot generally works best with southeast to southwest winds, and itโ€™s known for producing good lefts that can be a lot of fun for intermediate to expert surfers. Early mornings are usually the least crowded and offer prime conditions before the trade winds kick in.

Accessing San Juan is pretty straightforward, but be aware that it can get crowded during peak times. A localized vibe might kick in, so always be respectful of the locals. In terms of board types, you can bring a shortboard, funboard, longboard, or even a fish or bodyboard, depending on the conditions you're facing. Keep an eye on the surf forecast, especially during autumn and winter seasons when the swells can be more consistent.

Readme

Welcome! If youโ€™re new to surf forecasting, check out this quick guide.

Forecast Table

The forecast table (the section on the page with all the numbers) is designed to pack as much information in the screen as possible. Although intimidating at first, it will help you make informed decisions about the waves faster, trust me :D. The table consists of roughly four sections, time and predictions, wind, waves, and tides:

๐Ÿ”ฎ Time and predictions section

Here we show the forecast thour and the overall surf quality prediction. This is determined based on the wave, wind and tide quality prediction. These individual predictions can be found on the forecast map.

๐Ÿ’จ Wind section

The first row on the table (with the ๐Ÿ’จ icon) shows wind speed, direction and gust. The more the wind speed the more aggressive the color (from blue, green, orange to red).

๐ŸŒŠ Wave section

The waves section consists of three rows, one for wave height and direction, one for period and one for wave energy. Our algorithm chooses the "dominant wave" using spot-adjusted surf energy (depth + directional fit). This is usually the first swell partition, but during local storms it can switch to wind waves. If that happens, values are shown in gray and italic.

๐ŸŒ’ Tide section

The tide section consists of a row with the actual heights per hour (measured at the half hour) and a table that displays the flow of the tide and the extremes (lows and highs).

Forecast map

The forecast map consists of arrows. These arrows represent all wave partitions (swell partitions and wind wave partition) and the wind. This allows you to see things like: a secondary swell or wind waves messes up the surf, or the wind is just a tick offshore so very surfable. Click a metric label in the bottom left to bring that arrow to the front โ€” handy when arrows overlap.

Forecast Cheat Sheet

Short on time? Focus on wave energy. Itโ€™s the best single metric to gauge how big and powerful the waves will be.

Click any table cell to jump to that forecast hour. The map will update with forecast arrows, so you can see if wind and swell direction are lining up.

Use the table sidebar to switch units for height and speed.

Log your surf sessions to compare forecasts with real sessions and sharpen future predictions.

Models and Updates

Surfnerd blends multiple global and local wind and swell models using advanced interpolation and spatial techniques to create an "ensemble" forecast. Forecasts are refreshed hourly.

Surf Predictions

Our AI-driven algorithm scores surf quality, shown by green, orange, and gray dots. Each forecast hour is rated for wind, swell, and tide quality, then combined into an overall score. Hereโ€™s the scale:

Perfect
Good
Average
Bad or No Data

Session logs also feed the algorithm โ€” the more you log, the smarter your forecasts get.

With Surfnerd, no more "you should have been here yesterday"

Word lid van Surfnerd gratis
  • Sla favoriete spots op
  • Stel home spot in
  • Log surfsessies
Sign up with AppleSign up with Google
Delen
Surfnerd Logo
Serious tools for serious surf forecasting
Get 15-day forecasts, deeper swell data, real wave-power insights, and every model unlocked. Everything you need to call your next surf session.
  • 15-day
    forecast range
    (vs 5-day)
  • Shows
    wave energy
    (real power!)
  • Full
    swell breakdown
    (secondary and tertiary)
  • Access all
    models
    (vs only SN UNIFIED)
  • Shows
    confidence
    scores
    (more trust)
  • Compare
    models
    (more data)
Signup and Start your 7-day trial
Confidence

Confidence tells you how much the weather models agree on the forecast.

  • High confidence: Models agree closely; forecast is reliable.
  • Medium confidence: Some disagreement; conditions may shift slightly.
  • Low confidence: Models diverge; treat forecast with caution.

We calculate the wind confidence by comparing wind speed, gust and direction from multiple models (like GFS, ECMWF, Arome, and Harmonie) and seeing how closely they match. For wave certainty we compare height, period and direction, also on multiple models. They are weighted, meaning that some models count more than others, depending on how good they are for a certain spot.