Data lookup
Did your USDA hardiness zone change?
Compare the official 2012 and 2023 ZIP listings, see the listed half-zone difference, and understand what the result can and cannot tell you.
Every official ZIP listing, joined without guesses
40,480 ZIP records appear in both editions; 23,553 (58.2%) have different listed half-zones. These are record counts, not land-area, population, or climate statistics.
For publishers and researchers
Download the complete comparison
The CSV contains 41,142 exact ZIP rows, both official zone values, the signed half-zone change, and an explicit status for unmatched editions.
SHA-256 00980eb6c9b63b807855f9c5f4139b37612377336348e849e42345cb70680df4
Method and limits
What we compared
The 2012 edition represents the 1976-2005 period. The 2023 edition represents 1991-2020. Sprout joins the official OSU PRISM ZIP files by exact five-digit ZIP and never borrows a value for an unmatched ZIP. The source files assign a zone at each ZIP region's representative geographic center, so a large ZIP can contain more than one local zone. Alaska's map resolution also changed from 4 km to 800 m.
What this is not
This is an independent tabular comparison, not an official USDA Plant Hardiness Zone Map. It does not alter either source edition and does not use USDA-ARS or OSU logos.
Sources and redistribution terms: 2012 OSU PRISM dataset and 2023 OSU PRISM dataset. USDA's map-creation notes explain the climate periods, source changes, interpolation, and interpretation limits.
Suggested citation
Sprout Authority. USDA Plant Hardiness Zone ZIP Comparison, 2012 to 2023. Version 1.0.0 (2026-08-01). Exact-ZIP comparison derived from the official USDA-ARS and Oregon State University PRISM 2012 and 2023 listings. https://sproutauthority.com/tools/hardiness-zone-change
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<script>window.addEventListener("message",function(e){if(e.origin!=="https://sproutauthority.com"||e.data?.type!=="sprout-authority:resize")return;var f=document.getElementById("sprout-hardiness-zone-change");if(f)f.height=String(e.data.height)});</script>
<p style="font:14px/1.5 system-ui,sans-serif">Free <a href="https://sproutauthority.com/tools/hardiness-zone-change">Sprout Authority hardiness zone change lookup</a> by Sprout Authority.</p>The attribution link is included in the copied HTML.
Common questions
Why did my USDA hardiness zone change?
USDA says changes can reflect the newer 1991-2020 climate period, additional station data, and improved interpolation. A ZIP result alone cannot separate those causes.
Does a higher-numbered zone prove climate change?
No. USDA says hardiness-zone changes are not reliable evidence of global warming because the maps compare 30-year averages of annual extreme minimum temperatures and also differ in source data and methods.
Can I grow every perennial listed for my new zone?
No. A zone is one cold-temperature signal. Plant survival also depends on exposure, soil, moisture, establishment, winter duration, and local microclimates.
How was the ZIP comparison created?
Sprout Authority joined the official 2012 and 2023 OSU PRISM ZIP listings by exact five-digit ZIP. Missing ZIPs stay missing, and the half-zone change is the 2023 classification minus the 2012 classification in five-degree steps.
Need today's planning answer? Open the ZIP planting calendar