About The Zone Maps

Garden-Helper.com is pleased to offer you the USDA Plant Hardiness Zone Map as a tool for helping to discover what may grow well in your neck of the woods.

Introduction

This map supersedes U.S. Department of Agriculture Miscellaneous Publication 814, "Plant Hardiness Zone Map," which was revised in 1965. This 1990 version shows in detail the lowest temperatures that can be expected each year in the United States, Canada, and Mexico. These temperatures are referred to as "average annual minimum temperatures" and are based on the lowest temperatures recorded for each of the years 1974 to 1986 in the United States and Canada and 1971 to 1984 in Mexico. The map shows 10 different zones, each of which represents an area of winter hardiness for the plants of agriculture and our natural landscape. It also introduces zone 11 to represent areas that have average annual minimum temperatures above 40 F (4.4 C) and that are therefore essentially frost free.

How to Use the New Map

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 20 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 surrounding countryside. The map-contains as much detail as possible, considering the vast amount of data on which it is based and its size.

Click on any area within the United States to go to a close-up of that region

Or Click on your State abbreviation below to go to that region

AK  AL  AR  AZ  CA  CO  CT  DC  DE  FL  GA  HI  IA  ID  IL  IN  KS  KY

LA  MA  MD  ME  MI  MN  MO  MS  MT  NC  ND  NE  NH  NJ  NM  NV  NY

OH  OK  OR  PA  RI  SC  SD  TN  TX  UT  VA  VT  WA  WI  WV  WY

USDA Hardiness Zones and Average Annual Minimum Temperature Range

Zone	Fahrenheit	Celsius
1	Below -50 F	Below -45.6 C
2a	-50 to -45 F	-42.8 to -45.5 C
2b	-45 to -40 F	-40.0 to -42.7 C
3a	-40 to -35 F	-37.3 to -39.9 C
3b	-35 to -30 F	-34.5 to -37.2 C
4a	-30 to -25 F	-31.7 to -34.4 C
4b	-25 to -20 F	-28.9 to -31.6 C
5a	-20 to -15 F	-26.2 to -28.8 C
5b	-15 to -10 F	-23.4 to -26.1 C
6a	-10 to -5 F	-20.6 to -23.3 C
6b	-5 to 0 F	-17.8 to -20.5 C
7a	0 to 5 F	-15.0 to -17.7 C
7b	5 to 10 F	-12.3 to -14.9 C
8a	10 to 15 F	-9.5 to -12.2 C
8b	15 to 20 F	-6.7 to -9.4 C
9a	20 to 25 F	-3.9 to -6.6 C
9b	25 to 30 F	-1.2 to -3.8 C
10a	30 to 35 F	1.6 to -1.1 C
10b	35 to 40 F	4.4 to 1.7 C
11	above 40 F	above 4.5 C