According to the 2023 USDA Hardiness Zone Map McCone County, Montana is in Zones 3b (-35°F to -30°F), 4a (-30°F to -25°F) and 4b (-25°F to -20°F). There is no change from the 2012 USDA Hardiness Zone Map which has McCone County in also in Zones 3b (-35°F to -30°F), 4a (-30°F to -25°F) and 4b (-25°F to -20°F).