Planting Zones
Type in your ZIP code and get your USDA planting zone with the temperature it actually stands for, plus the older 2012 zone that seed catalogs and plant tags are still printing.
Look up your planting zone
How the zone number is worked out
A USDA planting zone is one number and one number only: the average annual extreme minimum temperature. Take the coldest night of each winter for thirty years, average those thirty readings, and see which 10°F band the answer falls in. That band is your zone.
Each whole zone is 10°F wide and splits into two halves of 5°F each. The half labeled a is the colder half, the half labeled b is the warmer half. So the arithmetic for any zone is:
bottom of zone = -60°F + (zone number - 1) × 10°F, then add 5°F for the b half.
Zone 6, for example, starts at -60 + (6 - 1) × 10 = -10°F. So 6a runs -10 to -5°F and 6b runs -5 to 0°F. Every row in the table below is generated from that formula rather than typed in, so it cannot drift.
Source: USDA Plant Hardiness Zone Map, 2023 revision, produced by the PRISM Climate Group at Oregon State University from 1991 to 2020 station data. The previous revision was published in 2012 from 1976 to 2005 data.
Planting zone chart: 1a to 13b
Every USDA zone, the coldest winter night it describes, and places that sit in it. Your own zone is highlighted once you run a lookup above.
| Zone | Coldest winter night, on average | In Celsius | Representative places |
|---|
Place names are broad regional examples meant to help you sanity check a number, not per-address assignments. Large metro areas frequently span two or three half-zones, and a city center usually runs a half-zone warmer than the countryside around it.
Keep planning
Your zone tells you what survives the winter. These tell you when to do the work.
Common questions
What does my planting zone actually tell me?
One thing: whether a perennial, shrub, tree, or bulb can be expected to survive an average winter where you live. It is a survival rating for permanent plants. It says nothing about summer heat, humidity, rainfall, soil, day length, or when your spring starts, and it is not a planting calendar.
Why do seed catalogs and plant tags disagree with this page?
Because many of them still print zones from the 2012 map. The USDA revised the map in 2023 using newer station data, and about half of all US locations moved one half-zone warmer as a result. A tag printed against the older map can therefore read one half-zone colder than the zone we show. That is the single most common reason two sources disagree, and it is why this tool shows you both.
Does a warmer zone mean I can plant earlier?
No, and this is the mistake that kills the most seedlings. Zone is built from winter lows, which is a completely different measurement from the date of your last spring frost. Seattle and Dallas share a zone and their last frost dates are weeks apart. For timing you need frost dates, not zones, so run the frost date lookup as well.
What is the difference between zone 6a and 6b?
Five degrees Fahrenheit at the bottom end of winter. Zone 6a averages a coldest night of -10 to -5°F, zone 6b averages -5 to 0°F. In practice that half-zone decides marginal plants: figs, rosemary, crepe myrtle, and many camellias are the ones that live in 6b and die in 6a.
Can I grow a plant rated for a warmer zone than mine?
Often yes, with effort. Grow it in a pot and move it indoors, plant it against a south-facing wall, mulch the crown heavily, or treat it as an annual and replace it. A zone rating describes an average winter, and gardeners beat it every year with microclimate and labor. What you cannot do is beat it by ignoring it.
My town straddles two zones. Which one should I use?
Use the colder one for anything expensive or permanent. A plant rated hardy to the colder of your two candidate zones is safe under either, and the cost of being wrong on a tree is a lot higher than the cost of being cautious.
Are these zones exact for my address?
No. This tool answers at the three-digit ZIP area level, which covers a large area and often more than one zone. Elevation is the usual culprit: a thousand feet of altitude is worth roughly a full zone. Treat the answer as the zone of your neighborhood and confirm with your county cooperative extension office before planting a fruit tree.