According to the 2023 USDA Hardiness Zone Map Millcreek, Utah is in Zones 6b (-5°F to 0°F), 7a (0°F to 5°F) and 7b (5°F to 10°F). There is no change from the 2012 USDA Hardiness Zone Map which has Millcreek in also in Zones 6b (-5°F to 0°F), 7a (0°F to 5°F) and 7b (5°F to 10°F).