According to the 2023 USDA Hardiness Zone Map Petersburg Census Area, Alaska is in Zones 4b (-25°F to -20°F), 5a (-20°F to -15°F), 5b (-15°F to -10°F), 6a (-10°F to -5°F), 6b (-5°F to 0°F), 7a (0°F to 5°F), 7b (5°F to 10°F), 8a (10°F to 15°F) and 8b (15°F to 20°F). This is a change from the 2012 USDA Hardiness Zone Map which has Petersburg Census Area in Zones 2a (-50°F to -45°F), 2b (-45°F to -40°F), 3a (-40°F to -35°F), 3b (-35°F to -30°F), 4a (-30°F to -25°F), 4b (-25°F to -20°F), 5b (-15°F to -10°F), 5a (-20°F to -15°F), 6a (-10°F to -5°F), 6b (-5°F to 0°F), 7a (0°F to 5°F), 7b (5°F to 10°F) and 8a (10°F to 15°F).