Tulip Test Gardens Plant Hardiness Zones Key USDA Hardiness Zones and Average Annual Minimum Temperature Range   (Back to Map)  USDA Zone  Temperature Range Example Cities           1   Below -50 F  (below -45.6C) 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  Barstow, 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 Hardiness Zone Map (clickable by region -U.S. National Arboretum) Facebook Pinterest Twitter © 1997 – 2024 Journey North. All rights reserved.