What Growing Zone Is Mason City?

Our records indicate the United States Department of Agriculture has given Mason City a growing zone designation of 6a. Sometimes also called the planting or hardiness zone, this zone number gives you an idea of what plants can and cannot grow in Mason City's climate based on the average extreme annual temperature.Our data is based on the latest 2023 USDA maps, which used Mason City's weather data from 1991 - 2020 in their analysis.

— Plate —IL · USDA hardiness

Latest IL growing zone map

If you are looking for plants suitable for growing in the Mason City area, head on over to our page on plants that grow well in Mason City, IL.

— Plate —IL · USDA hardiness

Latest IL growing zone map

The growing zone is a measure of the lowest temperature that a plant can survive based on average lowest year temperatures, helping you to decide what plants would grow best in your particular climate. Since Mason City is in growing zone 6a this means that plants there can survive temperatures as low as -10 to -5 degrees Fahrenheit. Plants for Mason City's climate should be chosen with this in mind, or plants should be moved inside to keep their core temperature in the right range if necessary.

Some zones may have been changed by the USDA as of 2023. To see if the Mason City area has been affected, refer to this map of half zone changes from the 2012 version of the USDA zones to the 2023 version.

The updated map shows that over half of the Southeast has warmed by about half a zone. For gardeners, that means you can now grow plants that tolerate a bit more heat and less frost than before. The tan areas reflect this shift. Meanwhile, the white areas had slight temperature changes, but not enough to move them into a new zone. In the Western U.S., a few spots shifted cooler. That’s not due to a colder climate, but because the new map uses a larger dataset, giving a more accurate picture of local conditions. It's important to keep track of these changes when planning your garden!

Ready to start planning your garden? Browse our curated list of plants recommended for Mason City, IL that are matched to this hardiness zone.

Hardiness Zone FAQ

Have questions about hardiness zones and what they mean for your garden? Check out our FAQ below for quick answers to common questions about USDA hardiness zones and how they affect plant selection in Mason City, IL.

Mason City's Growing Zone Details

Map of the Mason City Area

All Towns In IL

Plants For Other States

Looking for the best plants in a different area of the United States? Click on a button below to find plants that are ideal for that state's temperatures.