Zone Map
USDA Hardiness Zone Map
USDA Hardiness Zones and
Average Annual Minimum Temperature Range
| 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 |
USDA Miscellaneous Publication No. 1475. Issued January 1990.
Authored by Henry M. Cathey while Director, U.S. National Arboretum
Edited, formatted and prepared for the US National Arboretum web site by Ramon Jordan, March 1998 & Revised March 2001
U.S. National Arboretum, Agricultural Research Service, U.S. Department of Agriculture, Washington, DC 20002
Note: This publication is not copyrighted, and permission to reproduce all or any part of it is not required.
The Hardiness Zone Map is a valuable tool but it is not foolproof. There are a variety of reasons that can influence the hardiness of a given plant in a garden. These factors include: drainage, snow cover, exposure to wind, rainfall (or lack thereof) as well as fluctuans in temperatures.
For help in plant selection, refer to our article on Selecting Plants for Your Region
