NDBC Historical Archive Service
Provides quality-controlled historical observations from NDBC stations organized as annual files (prior years) and monthly files (current year) accessible at https://www.ndbc.noaa.gov/data/historical/. Measurement categories mirror the real-time service: standard meteorology, continuous winds, spectral wave data, ADCP currents, and oceanographic parameters. Data formats and column definitions are identical to the real-time files except that missing values use variable counts of nines (999, 9999, 99.0) rather than MM. A web-based historical observation search is available at histsearch.php and climatic summaries at climate.php.