How to Read NOAA Buoy Data for Surfing

By Nick Peterson · Updated 2026-08-21 · ~9 min read

Answer: On a NOAA NDBC buoy page, the four fields surfers need are WVHT (significant wave height — how big the swell is), DPD (dominant period — how much energy it has; 12s+ is groundswell), MWD (mean wave direction — where it's coming from, in degrees), and WSPD/WDIR (wind speed and direction). APD (average period) is lower than DPD and tells you how mixed the sea is. Read WVHT and DPD together: 1.2m (4ft) at 14s is a good groundswell; 1.8m at 7s is wind chop. Buoy readings are measurements, not forecasts — they tell you what the ocean is doing right now.

Every surf app you've used gets its "now" data from the same place: NOAA's National Data Buoy Center, a free public service with hundreds of moored buoys and coastal stations. Reading a buoy page directly takes two minutes to learn and gives you the one thing a forecast can't — the truth about current conditions. This guide decodes the fields, lists the flagship buoys for each US coast, and shows where that data is already turned into a surf report.

The buoy fields, decoded

Open any station at ndbc.noaa.gov and you'll see a table of abbreviations. Here's what each one means for surfing. Field names follow NDBC's own measurement descriptions.

Field	Full name	Units	What it means for surf
WVHT	Significant wave height	m (ft on some views)	Average height of the largest third of waves over the sample. Sets run 1.5–2× bigger. Open-ocean swell size, not face height at the beach. 1m ≈ 3.3ft.
DPD	Dominant wave period	seconds	Period of the most energetic swell. The surf number. Under 9s windswell; 9–12s mid-period; 12s+ groundswell.
APD	Average wave period	seconds	Average across all waves. Always lower than DPD. A big gap between APD and DPD means a clean long-period swell mixed with local chop; a small gap means one dominant sea state.
MWD	Mean wave direction	degrees true	Direction the dominant swell is coming from. 270 = from the west, 180 = from the south. Compare to your break's exposure window.
WSPD	Wind speed	m/s (or knots)	1 m/s ≈ 2 knots. Under 2.5 m/s (5 kt) is glassy; onshore over ~5–6 m/s (10–12 kt) blows most spots out.
WDIR	Wind direction	degrees true	Where the wind is blowing from. Offshore = from land toward the sea for your coast (east on the US West Coast, west on the East Coast).
GST	Gust	m/s	Peak wind in the sample; a big gap from WSPD means a gusty, messy day.
PRES / PTDY	Pressure / tendency	hPa	Falling fast = a front or storm approaching; expect wind to pick up.
WTMP	Water temperature	°C	Wetsuit decision. 15°C = 59°F.
SwH / SwP / SwD	Swell height / period / direction	m / s / compass	On the spectral "Detailed Wave Summary" view, NDBC separates groundswell (Sw) from wind waves (WWH/WWP/WWD). This is the cleanest surf view when two swells are running.
STEEPNESS	Wave steepness	text	"SWELL" = long-period, organized. "AVERAGE"/"STEEP"/"VERY STEEP" = increasingly wind-driven and choppy.

How to read a buoy in 30 seconds

DPD first. Is there energy? 12s+ and you have groundswell. 7s and you're looking at chop.
WVHT with it. 1.0m at 14s is a fun day at most West Coast beaches; 1.0m at 7s is nothing. Convert: metres × 3.3 = feet.
MWD vs your break. 290° into a south-facing cove is a flat day no matter what WVHT says.
WSPD + WDIR at the nearest coastal station (not the offshore buoy — wind at the beach is what matters). Under 5 kt or offshore: go.
Trend. Click the station's plots. Rising WVHT with rising DPD is a new swell filling in; falling DPD means it's fading into windswell.

Then check tide — buoys don't report it. NOAA's tide stations do, and every LazySurfer spot page shows the nearest one. See best tide for surfing.

Offshore buoy vs nearshore buoy

Deep-water buoys 20–30 miles out (like 46042 or 44025) see the swell before it hits the coast — great for "is it coming?" — but report open-ocean size. Nearshore buoys (mostly the CDIP-operated stations on the West Coast, like 46221 or 46225) sit close to the break and better reflect what will actually arrive, with direction already bent by the coastline. When both exist, read the offshore one for the trend and the nearshore one for the now.

Flagship buoys by coast

Station IDs verified against NDBC on 2026-08-21. Click any ID for the live page.

US West Coast

Station	Name	Useful for
46029	Columbia River Bar — 20 NM west of the river mouth	Oregon/Washington coast, first look at Gulf of Alaska swells
46050	Stonewall Bank — 20 NM west of Newport, OR	Central Oregon
46026	San Francisco — 18 NM west of SF	Ocean Beach, Marin, Santa Cruz north
46042	Monterey — 27 NM WNW of Monterey	Santa Cruz and Monterey Bay; the classic NorCal surf buoy
46221	Santa Monica Bay, CA	Malibu, South Bay LA (nearshore)
46225	Torrey Pines Outer, CA	North San Diego County (nearshore)

Hawaii

Station	Name	Useful for
51201	Waimea Bay, HI	Oahu North Shore — winter NW swells
51202	Mokapu Point, HI	Oahu windward side, trade-wind swell
51212	Barbers Point, Kalaeloa, HI	Oahu south shore — summer south swells

US East Coast

Station	Name	Useful for
44013	Boston — 16 NM east of Boston, MA	New England nor'easters
44097	Block Island, RI	Rhode Island, eastern Long Island (nearshore)
44025	Long Island — 30 NM south of Islip, NY	Long Island south shore, NJ north
44065	New York Harbor Entrance — 15 NM SE of Breezy Point	Rockaways, Long Beach, Monmouth County NJ
44009	Delaware Bay — 26 NM SE of Cape May, NJ	South Jersey, Delaware, Maryland
41013	Frying Pan Shoals, NC	Wrightsville, Carolina Beach, Outer Banks south
41009	Canaveral — 20 NM east of Cape Canaveral, FL	Cocoa Beach, Sebastian, Space Coast
41114	Fort Pierce, FL	Treasure Coast (nearshore)

Gulf Coast

Station	Name	Useful for
42035	Galveston — 22 NM east of Galveston, TX	Texas coast, tropical-system swell

See the buoy data already turned into a surf report

If decoding a table every morning isn't your idea of fun, LazySurfer's free spot pages show the nearest buoy's live WVHT/DPD/MWD, the nearest wind station and a two-day tide chart, alongside the conditions surfers at that break rated highest. A few examples, each with the buoy it reads:

Steamer Lane (Santa Cruz) — 46236 Monterey Canyon Outer
Malibu First Point — 46221 Santa Monica Bay
Scripps (La Jolla) — 46225 Torrey Pines Outer
Pipeline (Oahu) — 51210 Kaneohe Bay
90th St, Rockaways (NYC) — 44065 New York Harbor Entrance
Cocoa Beach Pier (FL) — 41113 Cape Canaveral Nearshore

In the app itself, the same readings feed a deep-learning model trained on your own logged sessions, so instead of "1.2m at 13s from 280°" you get a rating of how much you'd like it. Free with no ads; Pro is $7.99/mo, $29.99/6 mo or $49.99/yr. How it works.

Common mistakes

Reading WVHT as face height. It's open-ocean significant height; faces at the beach can be smaller (sheltered) or larger (focusing reef, long period).
Reading offshore-buoy wind as beach wind. Use the nearest coastal station (IDs ending in letters, like LJPC1 or SDHN4) for wind.
Ignoring APD. DPD 14s with APD 6s means one clean swell under a lot of chop — it can still be messy.
Forgetting buoys go offline. Stations drift, break, or get pulled for service. If the timestamp is hours old, check a neighbour.

Frequently asked questions

What does WVHT mean on a NOAA buoy?

WVHT is significant wave height: the average height of the largest one-third of waves measured during the sample period, reported in metres. It is the standard measure of swell size in open water; individual set waves can run 1.5 to 2 times larger.

What is the difference between DPD and APD?

DPD is the dominant wave period, the period of the swell carrying the most energy. APD is the average period of all waves in the sample. DPD is the number surfers use; APD is always lower, and a large gap between the two means a clean long-period swell is mixed with local wind chop.

What does MWD mean on a buoy report?

MWD is mean wave direction: the compass bearing in degrees true that the dominant swell is coming from. 270 means from the west, 180 from the south. Compare it to the range of directions your surf break is exposed to.

What buoy period is good for surfing?

A dominant period of 12 seconds or more indicates groundswell with enough energy for organized, powerful waves. Nine to twelve seconds is a usable mid-period swell. Under nine seconds is short-period windswell that produces weak, crumbly surf.

How do I convert buoy metres to feet?

Multiply by 3.28. A WVHT of 1.0 m is about 3.3 ft; 1.5 m is about 5 ft; 2.0 m is about 6.5 ft. Remember this is open-ocean swell height, not face height at the beach.

Which NOAA buoy should I check for surfing?

Use the deep-water buoy off your coast to see swells arriving (for example 46042 off Monterey, 44025 off Long Island, 41009 off Cape Canaveral, 51201 at Waimea Bay) and a nearshore buoy, if one exists, to see what will actually reach the beach. Check wind at the nearest coastal station rather than the offshore buoy.

Sources

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