What Growing Zone Is Hilmar-Irwin?

Our records indicate the United States Department of Agriculture has given Hilmar-Irwin a growing zone designation of 9a. Sometimes also called the planting or hardiness zone, this zone number gives you an idea of what plants can and cannot grow in Hilmar-Irwin's climate based on the average extreme annual temperature.Our data is based on the latest 2023 USDA maps, which used Hilmar-Irwin's weather data from 1991 - 2020 in their analysis.

map of growing zone 9a (Northern California)map of growing zone 9aLatest CA growing zone map

If you are looking for plants suitable for growing in the Hilmar-Irwin area, head on over to our page on plants that grow well in Hilmar-Irwin, CA.

Cluck Around Sign

Cluck Around Sign

Whimsical sign for your chicken coop area.
Deluxe Plastic Watering Can

Deluxe Plastic Watering Can

High-capacity watering can with comfortable grip and precise spout.
Metal Arbor Trellis

Metal Arbor Trellis

Decorative arbor trellis for climbing plants and garden entrance.
Rustic Iron Garden Trellis

Rustic Iron Garden Trellis

Sturdy trellis for supporting climbing plants and vines.
Raised Garden Bed Kit

Raised Garden Bed Kit

Easy-to-assemble raised garden bed for better soil control and drainage.
map of growing zone 9a (Northern California)map of growing zone 9aLatest CA 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 Hilmar-Irwin is in growing zone 9a this means that plants there can survive temperatures as low as 20 to 25 degrees Fahrenheit. Plants for Hilmar-Irwin'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 Hilmar-Irwin 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!

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 Hilmar-Irwin, CA.

The USDA hardiness zone is 9a for Hilmar-Irwin. This is sometimes also referred to as the growing or planting zone. These terms are used interchangeably.

Hilmar-Irwin's Growing Zone Details

USDA Growing Zone: 9a

Zip Codes:
95324

Longitude: -120.8504

Latitude: 37.4045

Lowest Avg Temperatures (F): 20 to 25

Metal Arbor Trellis

Metal Arbor Trellis

Decorative arbor trellis for climbing plants and garden entrance.
Raised Garden Bed Kit

Raised Garden Bed Kit

Easy-to-assemble raised garden bed for better soil control and drainage.
Cluck Around Sign

Cluck Around Sign

Whimsical sign for your chicken coop area.
Hydroponic Garden Grow Kit

Hydroponic Garden Grow Kit

Grow fresh herbs and vegetables year-round with this indoor hydroponic garden system.
Raised Garden Planter

Raised Garden Planter

Elevated planter for easy access and better drainage.

Map of the Hilmar-Irwin Area

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Small Greenhouse Kit

Small Greenhouse Kit

Compact greenhouse perfect for small spaces.
Shiitake Mushroom Kit

Shiitake Mushroom Kit

Grow your own delicious shiitake mushrooms at home.
Metal Seed Storage Box

Metal Seed Storage Box

Organized storage solution for your seed collection.
Wooden Chicken Coop

Wooden Chicken Coop

Spacious and secure home for your backyard chickens.
Cluck Around Sign

Cluck Around Sign

Whimsical sign for your chicken coop area.

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.

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Deluxe Plastic Watering Can

Deluxe Plastic Watering Can

High-capacity watering can with comfortable grip and precise spout.
Metal Seed Storage Box

Metal Seed Storage Box

Organized storage solution for your seed collection.
Rustic Iron Garden Trellis

Rustic Iron Garden Trellis

Sturdy trellis for supporting climbing plants and vines.
Raised Garden Planter

Raised Garden Planter

Elevated planter for easy access and better drainage.
Wooden Chicken Coop

Wooden Chicken Coop

Spacious and secure home for your backyard chickens.

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