Zone 6b

Hardiness Zone 6b

USDA hardiness zone 6b has an average coldest winter night of -5 to 0 °F (-21 to -18 °C). On the 2023 map it covers ZIP codes in 33 states, mostly Ohio, Pennsylvania and Missouri. Cities in zone 6b include Cincinnati, OH; Detroit, MI; Columbus, OH.

Average coldest night

-5 to 0 °F

-21 to -18 °C

States with zone 6b

ZIP codes in zone 6b

5,271

Check your own zone

States in zone 6b

State	ZIP codes	Share of state
Ohio	784	56%
Pennsylvania	761	36%
Missouri	521	46%
Kansas	401	54%
West Virginia	364	43%
New York	320	15%
Massachusetts	281	42%
Illinois	260	17%
Connecticut	252	60%
Indiana	226	24%
Michigan	222	19%
Kentucky	187	20%
Washington	88	12%
Idaho	87	28%
New Jersey	76	11%
New Mexico	68	16%
Oregon	62	13%
Utah	57	17%
Rhode Island	40	45%
California	38	1%
Colorado	36	6%
Virginia	33	3%
Arizona	26	5%
Nevada	24	10%
Oklahoma	15	2%
Maine	10	2%
North Carolina	9	1%
Alaska	8	3%
Maryland	7	1%
Texas	4	<1%
New Hampshire	2	1%
Montana	1	<1%
Tennessee	1	<1%

Cities in zone 6b

Larger places where every ZIP code is zone 6b.

Zones: 2023 USDA Plant Hardiness Zone Map ZIP code data, USDA Agricultural Research Service and the PRISM Climate Group, Oregon State University (official map). Place names: GeoNames (CC BY 4.0). Each ZIP code gets one zone, but a ZIP code can cross a zone line, and hills, valleys and towns can be warmer or colder than the zone shown.

About the Hardiness Zone Map

The Hardiness Zone Map finds your USDA plant hardiness zone, also called your planting or growing zone, from your ZIP code. Zones are based on the average coldest winter night of the year: each zone is 10 °F wide and split into a and b halves of 5 °F, from zone 1a in Alaska to 13b in Puerto Rico. Plant labels and seed packets give the coldest zone a plant can survive, so knowing your zone tells you which perennials, shrubs and trees can stay outside all winter. Zones come from the official 2023 USDA map ZIP code data for all 50 states, Washington DC and Puerto Rico.

How to use it

1 Enter your 5-digit ZIP code and press Find my zone.
2 Read your zone and the average coldest winter temperature it stands for.
3 Open your state to see its zones and the zone of every city.
4 Choose plants rated for your zone number or a colder (lower) one.

Frequently asked questions

What is the lowest temperature in zone 6b?

In zone 6b the coldest night of the year averages -5 to 0 °F (-21 to -18 °C). That is an average over 1991–2020, so a hard winter can go lower.

Which states have zone 6b?

Zone 6b is found in Ohio, Pennsylvania, Missouri, Kansas, West Virginia, New York, Massachusetts, Illinois, Connecticut, Indiana, Michigan, Kentucky, Washington, Idaho, New Jersey, New Mexico, Oregon, Utah, Rhode Island, California, Colorado, Virginia, Arizona, Nevada, Oklahoma, Maine, North Carolina, Alaska, Maryland, Texas, New Hampshire, Montana and Tennessee.

What is the difference between zone 6a and 6b?

Zone 6b is 5 °F warmer than 6a. Zone 6a has winter lows of -10 to -5 °F, and zone 6b -5 to 0 °F. Plant labels often give only the number, which covers both halves.

What plants grow in zone 6b?

Plants labelled hardy to zone 6 or colder (a lower number) should survive a zone 6b winter. Plants rated only for warmer zones may be damaged by frost unless grown in pots and brought in, or given shelter.

Related tools

Visited Places Map

Colour the countries, states and provinces you’ve been to, share your map and send friends places to visit

Where Food Grows

See which countries grow the most rice, mango, coffee, cocoa and 69 more crops on an animated world map

Unit Converter

Convert units of measurement

Date Calculator

Days between dates, add days, and working days with holidays

Taste Map

The most famous dish and street food of 193 countries: tick the ones you’ve tried and colour your world map

Where Animals Live

See every country where tigers, lions, pandas, penguins, hilsa and 200 more wild animals and fish live