Tool
Frost date lookup
Your average last spring frost and first fall frost, plus your USDA zone, from the nearest NOAA station. The foundation for every planting date.
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The embed resizes itself as answers open, with visible Sprout attribution and a link back to the full tool.
Publisher code
<iframe id="sprout-frost-dates" src="https://sproutauthority.com/embed/frost-dates" title="Sprout Authority frost date lookup" width="100%" height="420" loading="lazy" style="border:0;width:100%"></iframe>
<script>window.addEventListener("message",function(e){if(e.origin!=="https://sproutauthority.com"||e.data?.type!=="sprout-authority:resize")return;var f=document.getElementById("sprout-frost-dates");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/frost-dates">Sprout Authority frost date lookup</a> by Sprout Authority.</p>The attribution link is included in the copied HTML.
For publishers and researchers
Download the complete ZIP dataset
The CSV contains 40,502 ZIP rows, nearest-station assignments, 10%, 50%, and 90% freeze normals, station distance, USDA 2023 zone, and directly derived growing-season lengths.
SHA-256 22032060118a3eb5808ec070ddce8d5c6a052f13cb52b27fa79aa7bb191004e5
Method
Each ZIP is assigned to the nearest NOAA station from its Census ZCTA representative point. ZIPs without a ZCTA use the documented prefix-centroid fallback. The table does not estimate conditions between stations.
Limits
These are station normals, not address-level forecasts. Topography, water, urban heat, and other microclimates can shift actual freeze dates. Empty fields remain explicit.
Sources: NOAA NCEI U.S. Climate Normals, USDA 2023 hardiness-zone ZIP listings, and Census 2024 ZCTA Gazetteer. This transformed table is not an official agency product.
Suggested citation
Sprout Authority. NOAA 1991-2020 Frost Dates by ZIP. Version 1.0.0 (2026-08-01). Derived from NOAA NCEI U.S. Climate Normals, USDA 2023 hardiness-zone ZIP listings, and Census 2024 ZCTA representative points. https://sproutauthority.com/tools/frost-dates