{
  "schema_version": 1,
  "title": "WhenToApplyPreEmergent ZIP/ZCTA Growing Degree Days (base 50°F)",
  "version": "2026-07-16",
  "generated_at": "2026-07-16T00:00:00.000Z",
  "source_year": 2026,
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    "minimum_observation_end_date": "2026-07-09",
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  "row_count": 33642,
  "available_row_count": 33622,
  "unavailable_row_count": 20,
  "state_summary_row_count": 51,
  "gdd_base_f": 50,
  "station_candidate_count": 8,
  "freshness_max_lag_days": 7,
  "source_metadata": {
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        "schemaVersion": 1,
        "source": "https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2023_Gazetteer/2023_Gaz_zcta_national.zip",
        "sourceVintage": "2023 U.S. Census ZCTA Gazetteer",
        "censusZctaCount": 33791,
        "zctaAndSupplementalCount": 33794,
        "supplementalZipCount": 3,
        "retrieved_on": "2026-07-16"
      },
      "stateRelationship": {
        "schemaVersion": 1,
        "source": "https://www2.census.gov/geo/docs/maps-data/data/rel2020/zcta520/tab20_zcta520_county20_natl.txt",
        "sourceVintage": "2020 Census ZCTA5-to-County Relationship File",
        "assignmentMethod": "State containing the largest total ZCTA land-area share across all intersecting counties",
        "coverage": "50 states and the District of Columbia; territories are excluded",
        "zctaCount": 33642,
        "retrieved_on": "2026-07-16"
      }
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  "license": "CC-BY-4.0 for the project compilation, schema, documentation, and QA metadata; underlying U.S. government source observations and geography retain their source status.",
  "citation": "WhenToApplyPreEmergent.com (2026-07-16). WhenToApplyPreEmergent ZIP/ZCTA Growing Degree Days (base 50°F) [Data set]. https://whentoapplypreemergent.com/datasets/gdd/2026-07-16/",
  "qa": {
    "rows_sorted_by_zcta": true,
    "unique_zcta_count": 33642,
    "public_field_count": 20,
    "stale_available_rows": 0,
    "modeled_soil_temperature_included": false
  },
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