About these tools

Home Garden Lot Tools is the data side of Home Garden Lot, a site of practical, tested guides for growing food and improving your home. We build free tools on public data and show exactly where every number comes from.

Frost dates: data and method

• Source: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (annual/seasonal, by station). NOAA computes freeze-date probabilities from 30 years of daily minimum temperatures.
• Stations: 7,247 U.S. stations that publish 32°F freeze probabilities. Stations with too few freezes are marked "rare"; stations where a freeze can happen in any month are marked "any month".
• ZIP matching: each of 33,791 ZIP codes is placed at its Census Bureau 2024 ZCTA centroid and matched to the 3 nearest stations by straight-line distance. The nearest station is shown first, with its distance and elevation so you can judge how well it fits your garden.
• Limits: distance is not everything. A station 10 miles away but 2,000 ft higher can be colder than one 25 miles away at your elevation, so compare the nearby stations. About 234 remote ZIP codes are more than 50 miles from any station.
• Updates: the data is rebuilt automatically every January from NOAA's files and whenever the build script changes. Last built 2026-10-29.

Who makes these tools

Home Garden Lot is an independent, reader-supported site. The people behind the site are on the About page, and how we research, use AI tools and correct errors is in our Editorial Policy. Found a problem with a number? Tell us and we'll check it against the source.

Privacy

The tools run in your browser. ZIP codes you enter are not sent to us; your browser downloads a small data file for your ZIP prefix and remembers your last ZIP on your device only. See the privacy notice.