Reading a buoy report: wind, waves and period
TexCast's Coast page shows wind and waves from NOAA buoys near the Texas coast. The numbers come with short names, metric units and some ideas that are easy to misread, such as "significant" wave height. This guide explains what NOAA's National Data Buoy Center (NDBC) says each one is, how to turn them into units you use, and what a wave period tells you that the height does not. It does not tell you whether to go out. TexCast shows readings from public sources, and it is not a weather warning or rescue service.
What a buoy report says
- Wind direction is the direction the wind is coming from, in degrees clockwise from true north (NDBC).
- Wind speed is an average: over eight minutes at a buoy and two minutes at a land station, reported hourly, in meters per second (NDBC).
- Gust is the peak 5 or 8 second speed within that period (NDBC). It cannot be lower than the wind speed.
- Significant wave height (WVHT) is the average of the highest one-third of all the wave heights during a 20 minute period, in meters (NDBC). Because it is an average of the larger waves, some individual waves are taller than the number.
- Dominant wave period (DPD) is the period of the waves with the most energy, in seconds: the time between two crests (NDBC).
- Average wave period (APD) is the average of all the waves during the 20 minutes.
- Mean wave direction (MWD) is the direction the waves at the dominant period are coming from.
- Pressure, air temperature and sea surface temperature are also reported. Missing values appear as MM, and NDBC says fewer than half of its buoy stations report directional wave data.
Turn the numbers into units you use
NDBC's real-time files give speeds in meters per second and heights in meters, though its station pages can show imperial units. A quick reference: one meter per second is about 2.24 miles per hour and 1.94 knots, and one meter is about 3.28 feet. Move the sliders to see a reading in miles per hour, knots and feet.
An interactive drawing goes here in the app.
Height is only half the story: period and steepness
NDBC separates waves into two kinds. Wind-waves are made, or were recently made, by the local wind, and arrive at a lower period, meaning more often. Swell is not made by the local wind and arrives at a higher period, with a longer distance between crests. A few buoys report swell and wind-wave heights separately. When both are present, NDBC says the overall significant height should equal the square root of the sum of the squares of the two. NDBC also labels waves VERY STEEP, STEEP, AVERAGE or SWELL, and says that for a given height, steep waves are a more serious threat to capsizing vessels than broad swell; it works the label out by comparing height and period with climatology. NDBC gives no cutoffs, so TexCast does not invent any. This drawing shows why period matters: the same height can be a gentle roll or a short, steep chop.
An interactive drawing goes here in the app.
Wavelength here uses the standard deep-water relation, about 1.56 times the period squared in meters. Near the beach, in shallow water, waves behave differently, and a buoy is not on your fishing spot, so use it as a nearby reference, not a measurement of your water.
How old is the reading?
NDBC times are in UTC (the files use "YYYY MM DD hh" in GMT), and a buoy can go offline. TexCast shows each reading with the time it was observed and marks it stale after 3 hours. Check the time before you trust a number.
An interactive drawing goes here in the app.
Using it
- Start with the observed time, then the wind and its direction, then wave height and period together.
- Compare with the tide for the same hours. See how the tide works, since wind and tide together shape what the water does at your spot.
- See what that means on your kind of water: surf fishing, pier fishing and bay fishing.
- The nearest buoy is often miles away from your spot, and bays, passes and jetties change what the water does. Treat the buoy as one input.
On TexCast
For more reading, we suggest these articles
- NOAA National Data Buoy Center: Measurement Descriptions and Units (checked 2026-10-09)
- NOAA National Data Buoy Center: Glossary of Terms for Wave Information (checked 2026-10-09)
Home · Rivers · Lakes · Coast · Trout stocking · State parks · Learning Center · About · Privacy · Terms
Contact: hello@texcastfishing.com