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CalcSpan/Gardening, planting and frost calendars/Frost Date Calculator By Zip/85001
Preselected calculator · zip

Frost Date Calculator By Zip
85001.

85001 is applied to the real calculator input below. Review the visible assumptions and source scope, then adjust any details that differ from your situation.

Preselected value85001Match a ZIP to nearby NOAA 1991–2020 32°F probability dates, with the station, distance and USDA zone kept explicit. Inputs stay in your browser.
Browse zip1000120001303013310160601752018020285001900019410598101021081910332801482015540163101701127310284101
Preselected reference value85001This value is applied to the real calculator input. Adjust the remaining assumptions and verify the visible source before relying on the result.
Reference calculation

Enter your details.

ZIP matching uses the bundled Census/NOAA file in this browser; the ZIP is not uploaded.

Matched locally to a nearby NOAA climate-normal station; the ZIP is not uploaded.
NOAA normals supply month/day probabilities; this year places them on your calendar.
Probability that the last spring freeze occurs later, or the first fall freeze occurs earlier, than the shown date.
Leave blank for the locally matched station, or paste an annual/seasonal normals station ID.

Plain-date semantics · start date is not counted unless the result explicitly says inclusive.

Your result
Load the official 32°F climate normals

CalcSpan matches the ZIP locally to a nearby NOAA 1991–2020 climate-normal station, then applies the selected probability threshold. USDA hardiness zone is shown separately and never used to invent frost dates.

Why this result
ZIP Code85001
Planning year2026
Probability threshold10%Chance the last spring freeze is later / first fall freeze is earlier than the shown date
NOAA station overrideAutomatic nearby-station match
USDA 2023 hardiness zoneLoaded with the local ZIP reference
NOAA climate stationLoaded after Calculate span

Calculate to load the current reference data before saving.

Read before relying

Context matters.

  • A ZIP is a search aid, not a weather station. If the automatic station differs materially in elevation, coast exposure or terrain, use the NOAA station override.
  • USDA hardiness zones summarize annual extreme minimum temperature and are not frost dates.
Rule set 2.0.0

Sources & scope

Source & calculation QA reviewed

The calculation guide and this source trail show what the result means, where the rule came from and when it was last reviewed. This is source-and-calculation QA, not a claim of medical, legal, tax or other professional review; time-sensitive decisions still belong with the linked authority.

NOAA NCEI · SRC-NOAA-NORMALS-001U.S. Climate NormalsSource retrieved 2026-08-19NOAA NCEI · SRC-NOAA-ANNUAL-NORMALS-001U.S. Annual/Seasonal Climate Normals 1991–2020, version 1.0.1Source retrieved 2026-08-20U.S. Census Bureau · SRC-CENSUS-ZCTA-0012025 Gazetteer ZIP Code Tabulation AreasSource retrieved 2026-08-20USDA ARS · SRC-USDA-PHZM-001Plant Hardiness Zone MapSource retrieved 2026-08-19USDA ARS / OSU PRISM · SRC-USDA-PHZM-ZIP-0012023 Plant Hardiness Zone ZIP Code ListingsSource retrieved 2026-08-20
JurisdictionUnited States — NOAA 1991–2020 station normals, Census ZCTA matching and USDA 2023 hardiness-zone reference
Last reviewed2026-08-20
Next review due2027-02-20
Review scopeCalcSpan source & calculation QA
PrivacyNo input upload