Zones 2-10 in the map have been subdivided into light and dark colored sections (a and b) that represent 5° F (2.8° C) differences within the 10° F (5.6° C) zone. The light color of each zone represents the colder section; the dark color, the warmer section.
Zone 11 represents any area where the average annual minimum temperature is above 40° F (4.4° C).
The map shows twenty latitude and longitude lines. Areas above an arbitrary elevation are traditionally considered unsuitable for plant cropping and do not bear appropriate zone designations. There are also island zones that, because of elevation differences, are warmer or cooler than the surrounding areas and are given a different zone designation.
Note that many large urban areas carry a warmer zone designation than the surroundingcountryside. The maps contain as much detail as possible, considering the vast amount of data on which it is based and its size.
| Zone | Fahrenheit | Celsius | Example Cities |
| 1 | Below -50 F | Below -45.6 C | Fairbanks, Alaska; Resolute, Northwest Territories (Canada) |
| 2a | -50 to -45 F | -42.8 to -45.5 C | Prudhoe Bay, Alaska; Flin Flon, Manitoba (Canada) |
| 2b | -45 to -40 F | -40.0 to -42.7 C | Unalakleet, Alaska; Pinecreek, Minnesota |
| 3a | -40 to -35 F | -37.3 to -39.9 C | International Falls, Minnesota; St. Michael, Alaska |
| 3b | -35 to -30 F | -34.5 to -37.2 C | Tomahawk, Wisconsin; Sidney, Montana |
| 4a | -30 to -25 F | -31.7 to -34.4 C | Minneapolis/St.Paul, Minnesota; Lewistown, Montana |
| 4b | -25 to -20 F | -28.9 to -31.6 C | Northwood, Iowa; Nebraska |
| 5a | -20 to -15 F | -26.2 to -28.8 C | Des Moines, Iowa; Illinois |
| 5b | -15 to -10 F | -23.4 to -26.1 C | Columbia, Missouri; Mansfield, Pennsylvania |
| 6a | -10 to -5 F | -20.6 to -23.3 C | St. Louis, Missouri; Lebanon, Pennsylvania |
| 6b | -5 to 0 F | -17.8 to -20.5 C | McMinnville, Tennessee; Branson, Missouri |
| 7a | 0 to 5 F | -15.0 to -17.7 C | Oklahoma City, Oklahoma; South Boston, Virginia |
| 7b | 5 to 10 F | -12.3 to -14.9 C | Little Rock, Arkansas; Griffin, Georgia |
| 8a | 10 to 15 F | -9.5 to -12.2 C | Tifton, Georgia; Dallas, Texas |
| 8b | 15 to 20 F | -6.7 to -9.4 C | Austin, Texas; Gainesville, Florida |
| 9a | 20 to 25 F | -3.9 to -6.6 C | Houston, Texas; St. Augustine, Florida |
| 9b | 25 to 30 F | -1.2 to -3.8 C | Brownsville, Texas; Fort Pierce, Florida |
| 10a | 30 to 35 F | 1.6 to-1.1 C | Naples, Florida; Victorville, California |
| 10b | 35 to 40 F | 4.4 to 1.7 C | Miami, Florida; Coral Gables, Florida |
| 11 | above 40 F | above 4.5 C | Honolulu, Hawaii; Mazatlan, Mexico |
Go Back to the USDA Hardiness Zone Map
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Search The Garden Helper:
FAQs
A location's zone is determined by its average annual extreme minimum winter temperature. On the map, zones range from 1a to 13a, with zone 1a representing -60º to -55º F and zone 13a representing 65º to 70º F. The map is interactive, and you can find your exact location's zone by typing in your zip code.
What is the USDA hardiness rating system? ›
The USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which perennial plants are most likely to thrive at a location. The map is based on the average annual extreme minimum winter temperature, displayed as 10-degree F zones and 5-degree F half zones.
What temperature range is zone 5 USDA? ›
USDA Hardiness Zone 5 has winter temperatures between negative ten and negative twenty degrees Fahrenheit, enabling home growers to cultivate many varieties of cold-hardy herbs, fruit trees, flowers, and shrubs.
What states are in the hardiness zone 7? ›
From east to west, it begins in small areas of southern Connecticut. It then stretches south through Virginia, east through Tennessee and northern Arkansas, and southwest through the Texas panhandle and New Mexico, then narrows and winds north through Nevada, California, Oregon, and Washington.
Are USDA hardiness zones changing? ›
Climate Change
Compared to the 2012 and 1990 maps, zone boundaries in this 2023 edition have shifted in many areas. The new PHZM is generally about one quarter-zone warmer than reported in the 2012 PHZM throughout much of the United States, as a result of a more recent averaging period (1976-2005 vs. 1991-2020).
What does the term hardiness mean? ›
noun. the capacity for enduring or sustaining hardship, privation, etc.; capability of surviving under unfavorable conditions. courage; boldness; audacity.
What is the lowest temperature in Zone 7? ›
Plants in Zone 7 can handle temperatures of 0°F to 10°F. You can find this zone in some parts of Washington and Oregon and down through upper Texas, Oklahoma, and most of the way through Virginia and North Carolina.
What is the difference between zone 5a and 5b? ›
Subset Zone Temperatures
Zone 5: The minimum average range of temperatures is -10° to -20°F. Zone 5a: This subzone has a minimum average temperature of -15° to -20° F. Zone 5b: This subzone has a minimum average temperature of -10° to -15°F.
What is the lowest temperature in Zone 8? ›
The minimum average temperature of Zone 8a is 10-15° Fahrenheit, and the minimum average temperature of Zone 8b is 15-20° Fahrenheit. Unusual weather patterns and events can cause these temps to fluctuate, and despite the averages, the coldest temps in Zone 8 rarely fall below 32°.
What is the coldest hardiness zone in the US? ›
Cold Hardiness zones are based on the average annual minimum temperature in a given area of the country, with USDA Zone 1 being the coldest at minus 50 degrees F and USDA Zone 13 the warmest at above 60 degrees F.
The warmest zone in the 48 contiguous states is the Florida Keys (11b) and the coldest is in north-central Minnesota (2b). A couple of locations on the northern coast of Puerto Rico have the warmest hardiness zone in the United States at 13b.
What is the difference between zone 7a and 7b? ›
Zone 7a: This subzone has a minimum average temperature of 0° to 5°F. Zone 7b: This subzone has a minimum average temperature of 5° to 10°F.
What is the difference between zone 6a and 6b? ›
Zone 6 has two subzones: 6a and 6b. Zone 6a has an average minimum temperature of negative five to negative ten degrees Fahrenheit. Zone 6b experiences minimum temperatures of zero to negative five degrees Fahrenheit.
Is zone 6 colder than zone 8? ›
Zone 6: -10 to 0 degrees Fahrenheit. Zone 7: 0 to 10 degrees Fahrenheit — this is me! Zone 8: 10 to 20 degrees Fahrenheit. Zone 9: 20 to 30 degrees Fahrenheit.
Is Virginia zone 7a or 7b? ›
This means about half of the country has moved into a warmer hardiness zone. Here at home, Albemarle County and much of Central Virginia are now classified as zone 7b, rather than the previous 7a. Elsewhere in the Commonwealth, nearly every city in the Hampton Roads region has moved from zone 8a to zone 8b.
