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MAY 1, 2026
Established 2011

The Plant Guide Online

Growing zones & plants for every town in America

What Growing Zone Is Niwot?

Our records indicate the United States Department of Agriculture has given Niwot 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 Niwot's climate based on the average extreme annual temperature.Our data is based on the latest 2023 USDA maps, which used Niwot's weather data from 1991 - 2020 in their analysis.

— Plate —CO · USDA hardiness
map of growing zone 6a
Latest CO growing zone map

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

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Show Niwot's growing zone on my site

— Plate —CO · USDA hardiness
map of growing zone 6a
Latest CO 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 Niwot is in growing zone 6a this means that plants there can survive temperatures as low as -10 to -5 degrees Fahrenheit. Plants for Niwot'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 Niwot 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 Niwot, CO 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 Niwot, CO.

№ 01What hardiness zone is Niwot, CO?+

The USDA hardiness zone is 6a for Niwot. This is sometimes also referred to as the growing or planting zone. These terms are used interchangeably.

№ 02What does growing zone 6a mean for Niwot, CO?+

Growing zone 6a means that plants in Niwot, CO can survive temperatures as low as -10 to -5 degrees Fahrenheit. This zone designation helps you choose plants that will thrive in your local climate conditions.

№ 03How do I use the growing zone information for Niwot?+

Keep your growing zone of 6a in mind when choosing plants for Niwot. The growing zone tells you the average low temperatures that occur each year in Niwot. If you select plants from zones other than 6a, then you may need to provide additional care during the coldest months of the year.

№ 04Has Niwot's growing zone changed?+

The USDA updated their hardiness zone maps in 2023. As a result, Niwot may have experienced zone changes. Some areas of the Southeast warmed by half a zone, while areas of the Western United States had their zones lowered as a result of additional data becoming available.

№ 05What plants grow best in zone 6a?+

Visit our page on the best plants for Niwot to see a full list recommendations for the area.

№ 06Can I grow plants from other zones in Niwot?+

While you can try plants from other zones, they may need winter protection or indoor shelter during cold spells. Focus on plants recommended for Niwot's climate for the best results.

Niwot's Growing Zone Details

USDA Growing Zone: 6a

Zip Codes:

Longitude: -105.1552

Latitude: 40.098

Lowest Avg Temperatures (F): -10 to -5

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Map of the Niwot Area

— Map —Lat 40.098, Lon -105.1552
Tile data © Google Maps

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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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