According to the 2023 USDA Hardiness Zone Map Chisago County, Minnesota is in Zones 4a (-30°F to -25°F) and 4b (-25°F to -20°F). This is a change from the 2012 USDA Hardiness Zone Map which has Chisago County in Zones 3b (-35°F to -30°F), 4a (-30°F to -25°F) and 4b (-25°F to -20°F).