USA Zone
USA Zone
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
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.
URL =
http://www.usna.usda.gov/Hardzone/hrdzon4.html