Daymet candidate status

Daymet is a candidate, not an implemented temperature source flavor. data.sources("temperature") therefore continues to return only reviewed sources.

The proposed integration maps Daymet V4/V4R1 daily tmax to the stable temperature noun and uses the climate_continuous_daily QA profile. The candidate revision is:

temperature.daymet@2026-08-26.1

Why it is blocked

ORNL documents spatially and temporally bounded NCSS requests returning CF-compliant NetCDF, but ORNL DAAC now requires a NASA Earthdata login for data downloads. The documented unauthenticated V4 endpoint returned HTTP 401 during this review. CubeDynamics records that as BLOCKED and UNAVAILABLE; it does not fabricate data or promote an unreviewed source.

• Daymet web services
• Daymet V4 product guide
• Current ORNL access guidance
• Earthdata login requirement

Promotion checklist

1. Supply EARTHDATA_TOKEN only in the online certification environment.
2. Run python scripts/run_live_source_certification.py --source daymet.
3. Review a tiny bounded NetCDF subset, provider version headers, schema drift, numerical QA, and diagnostic plot.
4. Add the checksum-controlled subset under tests/fixtures/real_data/.
5. Link its schema fingerprint and QA evidence in serving history.
6. Promote only after data.validate_promotion() accepts the complete record.

Daymet must not become the default or silently replace PRISM/gridMET.