NOAA NDBC buoy data
NOAA NDBC buoy data
NOAA's National Data Buoy Center publishes realtime observations from its moored and drifting buoys and C-MAN coastal stations as flat files over HTTPS, one file per station and data type (for example standard meteorological data at https://www.ndbc.noaa.gov/data/realtime2/41002.txt), covering wind, waves, sea surface temperature, pressure, air temperature and more. No account or key is needed.
Coverage
The realtime2 directory holds the current last-45-days window per station; most stations report hourly, with data typically available about 25 minutes after the hour (reporting frequency varies by station and can be checked on each station's page). NDBC asks users to "limit your retrievals to a minimal level" but states no numeric request cap.
Verdict
This is a US-government sea-state and marine-weather signal for adding wave height, wind and sea-surface-temperature context to shipping routes and port approaches, especially in US coastal and offshore waters. Realtime files have had only automated quality checks, so treat them as provisional, and keep retrieval frequency aligned with each station's actual reporting interval rather than polling faster than the data updates. For history beyond 45 days, use NDBC's separate historical archives.
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Use in your agent
Load a live NOAA NDBC buoy's realtime observations into pandas and Parquet. Checked against the provider's documentation on Nov 4, 2026.
Access
- No account or key. Flat files are served over HTTPS.
Request
curl 'https://www.ndbc.noaa.gov/data/realtime2/46042.txt'Format
Fixed-width-looking whitespace-delimited text: a #-prefixed column-name header, a units header, then one row per observation (newest first), with "MM" marking missing values.
Load into pandas and Parquet
Needs Python 3 with requests, pandas and pyarrow.
"""NOAA NDBC station 46042 realtime observations -> pandas -> Parquet. No key."""
import io
import requests
import pandas as pd
URL = "https://www.ndbc.noaa.gov/data/realtime2/46042.txt"
r = requests.get(URL, timeout=60)
r.raise_for_status()
lines = r.text.splitlines()
header = lines[0].lstrip("#").split()
df = pd.read_csv(io.StringIO("\n".join(lines[2:])), sep=r"\s+", names=header, na_values=["MM"])
df.to_parquet("ndbc_46042_realtime.parquet", index=False)
latest = df.iloc[0]
print(len(df), "observations; most recent", f"{int(latest['YY'])}-{int(latest['MM']):02d}-{int(latest['DD']):02d} {int(latest['hh']):02d}:{int(latest['mm']):02d} UTC")Run by us on 2026-11-04 (python 3.13.5 | pandas 3.0.6 | pyarrow 26.0.1 | requests 2.34.2). Result: 6350 observations; most recent 2026-11-05 04:10 UTC
Limits
- NDBC asks users to "limit your retrievals to a minimal level." No numeric threshold is published.
- Most stations report hourly; this station reports roughly every 10 minutes, so poll no faster than the station's own interval.
Quirks
- Not every station reports every data type; check which files exist for a given station_id first.
- Some stations go silent for extended periods (a different station checked the same day had not reported in a month) without being removed from the directory, so check the most recent timestamp rather than assuming freshness.
- C-MAN land stations use uppercase station IDs in file names.
Terms and attribution
- NDBC is a US federal government source; NOAA/NWS content on government servers is generally public domain unless marked otherwise.
- Realtime data has had only automated quality checks and carries no warranty of accuracy.
Sources
- https://www.ndbc.noaa.gov/faq/rt_data_access.shtml: “We ask that you limit your retrievals to a minimal level.”
- https://www.ndbc.noaa.gov/faq/rt_data_access.shtml: “The Realtime directory data/realtime2 contains the current (last 45 days) data.”
- https://www.weather.gov/disclaimer: “The information on National Weather Service (NWS) Web pages are in the public domain, unless specifically noted otherwise, and may be used without charge for any lawful purpose”
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