What Planting Zone Am I In?
Type your ZIP code or city to find your USDA plant hardiness zone. You'll see the winter low it's based on, what to look for on plant tags, and your average frost dates.
- Official USDA 2023 map data
- Every US ZIP code
- Average frost dates too
2 Your planting zone
Pick a place to updateExample: Plano, TX (75024). Search above for your own place.
In zone 8b, the coldest night of an average winter bottoms out at 15 to 20°F (−9.4 to −6.7°C). A perennial, shrub or tree labeled hardy to zone 8 or a colder zone should survive the winter here.
| Zone | 8b (the warmer half of zone 8) |
|---|---|
| Average extreme low | 15 to 20°F (−9.4 to −6.7°C) |
| This ZIP's average coldest night | 16.7°F (USDA) |
| Plant tags to look for | a zone range that includes 8, such as "zones 5–8" or "zones 6–10" |
| Pushing your luck | plants rated only for zone 9 or warmer |
Average last spring frost: Mar 7; first fall frost: Nov 21. Planting times come from these, not from the zone. See the frost date lookup for the full range.
The zone tells you what survives winter, not when to plant. The zone is based on the average coldest night, not the coldest ever, so a hard winter can go below this range. Low spots, hilltops and city centers can also run colder or warmer.
Quick answer
USDA planting zones run from 1 (coldest) to 13 (warmest), set by the average coldest winter night. Plano, Texas (ZIP 75024) is zone 8b, where winter lows average 15 to 20°F, so look for plants rated hardy to zone 8 or colder.
What a planting zone is
The USDA Plant Hardiness Zone Map splits the US into 13 zones by the average coldest night of the year. Each zone covers 10°F. Zone 1 in interior Alaska averages −60 to −50°F, and zone 13 in Puerto Rico and Hawaii averages 60 to 70°F. Each zone has an "a" half (colder) and a "b" half (warmer), 5°F each.
The 2023 map uses weather from 1991 to 2020. It's the version nurseries and plant tags use today.
Worked example: Plano, Texas
- ZIP 75024 is in zone 8b, so the coldest night of an average winter falls from 15 to 20°F.
- A shrub tagged "zones 5–9" or "hardy to zone 6" should come through a typical winter there.
- A plant rated only for zones 9 to 11 is a gamble; one cold winter can kill it.
- The zone doesn't tell you when to plant. Plano's average last spring frost is March 7, from our frost date lookup.
Planting zones for major US cities
| City | Zone | Average coldest night |
|---|---|---|
| New York, NY | 7b | 5 to 10°F |
| Chicago, IL | 6a | −10 to −5°F |
| Houston, TX | 9b | 25 to 30°F |
| Phoenix, AZ | 9b | 25 to 30°F |
| Philadelphia, PA | 7b | 5 to 10°F |
| Dallas, TX | 8b | 15 to 20°F |
| Austin, TX | 9a | 20 to 25°F |
| Denver, CO | 6a | −10 to −5°F |
| Seattle, WA | 9a | 20 to 25°F |
| Atlanta, GA | 8a | 10 to 15°F |
| Minneapolis, MN | 5a | −20 to −15°F |
| Boston, MA | 7a | 0 to 5°F |
| Nashville, TN | 7b | 5 to 10°F |
| Kansas City, MO | 6b | −5 to 0°F |
| Salt Lake City, UT | 7b | 5 to 10°F |
| Portland, OR | 8b | 15 to 20°F |
| Detroit, MI | 6b | −5 to 0°F |
| Columbus, OH | 6b | −5 to 0°F |
| Albuquerque, NM | 7b | 5 to 10°F |
| Las Vegas, NV | 9a | 20 to 25°F |
| Los Angeles, CA | 10b | 35 to 40°F |
| Miami, FL | 11a | 40 to 45°F |
Each city uses the ZIP code at its center. Large cities can span two half-zones.
How to use your zone
- Read the range on the tag. "Zones 5–9" means the plant survives winters in zone 5 and handles the summers in zone 9. Your zone should fall inside that range.
- Pick perennials, shrubs and trees by zone. Annuals and most vegetables live for one season, so the zone matters less for them. For those, plan by your frost dates.
- Go one zone colder for pots. Roots in a container above ground get colder than roots in the soil. Many gardeners pick plants rated one or two zones colder for pots left out all winter.
- Use your yard's warm and cold spots. A south-facing wall can carry a borderline plant through winter, and a low corner where cold air pools can kill one rated for your zone.
Did my zone change?
Possibly. USDA says the 2023 map runs about a quarter-zone (2.5°F) warmer than the 2012 map across much of the country. Some of that comes from better data and mapping methods, not only warmer winters. USDA also says a new zone is no reason to pull out plants that are doing well.
What the zone doesn't cover
The zone is built from average winter lows, not record lows, so a hard winter can still go colder. Summer heat, rainfall, humidity, wind and soil all affect what thrives. A plant that's hardy to zone 5 can still struggle in a hot, humid zone 8 summer. Local nurseries and your county extension office know which plants do well in your area.
Our lookup uses USDA's official 2023 ZIP code table from Oregon State University's PRISM group, which made the map. Details are on our how we calculate page.
Frequently asked questions
What planting zone am I in?
Enter your ZIP code or city in the lookup above. It uses USDA's 2023 Plant Hardiness Zone Map, the current official version.
What does the "a" or "b" after my zone mean?
Each zone covers 10°F and is split into two 5°F halves. "a" is the colder half and "b" the warmer. Zone 7a averages 0 to 5°F on the coldest night, and 7b averages 5 to 10°F.
Is a planting zone the same as a climate zone?
No. The USDA planting zone is for gardening and is based only on winter lows. The building climate zones (1 to 8) used for insulation come from the energy code and use heating and cooling needs. See our climate zone lookup for those.
Does my zone tell me when to plant vegetables?
No. Zones tell you which perennials survive winter. For planting dates, use your average last spring frost and first fall frost from our frost date lookup.
Why did my zone change from the old map?
The 2023 map uses 1991 to 2020 weather, while the 2012 map used 1976 to 2005. USDA says the new map is about a quarter-zone warmer across much of the country, partly from more stations and better mapping methods.
Last reviewed 2026-10-23. See how we calculate for our sources and assumptions.