Climatology Plugin for OpenCPN

This plugin visualises historical monthly weather and ocean patterns for voyage planning and supplies the established Climatology interface used by Weather Routing. It is not a forecast and its depth layer is not navigational bathymetry.

Dataset identity

Modern versioned bundles include dataset-manifest.json and DATASET_PROVENANCE.md in this data directory. They give the exact period, source product identifiers, processing choices, generator revision and SHA-256 checksums. The plugin version and dataset version are deliberately independent and are shown together on the About page.

Modern dataset sources

• Wind atlas and atmospheric fields: ECMWF ERA5.
• Sea-surface currents: NASA/JPL PO.DAAC OSCAR Final V2.
• Tropical cyclones: NOAA/NCEI IBTrACS v04r01.
• Sea-surface temperature: NOAA OISST v2.1.
• Bathymetry context: GEBCO 2026.
• ENSO classification: NOAA CPC ONI based on ERSSTv6.
• Lightning: the observed NASA LIS/OTD HRMC v2.3.2013 layer is retained (1995–2013); precipitation is not used as a proxy for lightning.

The intended common target period is 1995-01-01 through 2024-12-31. Where an authoritative product has shorter coverage, the exact per-product period in the manifest takes precedence.

Interpretation

The wind atlas contains eight directional-sector frequencies and mean speeds plus calm and gale probabilities. The current layer contains vector components; directions are interpolated through the components rather than as wrapped angles. Missing coastal cells are not treated as zero.

The plugin was created by Sean D'Epagnier and subsequently maintained by the OpenCPN plugin community. See the repository documentation for the implementation audit, legacy-format specification, source audit and full rebuilding procedure.