What Hardiness Zone Is Washington?

Q: What hardiness zone is Washington?

Washington is in USDA hardiness zones 6a–9b on the 2023 USDA Plant Hardiness Zone Map. Zone 8b is the most common, covering 37% of Washington's ZIP codes, and zone 9a covers 19%. Enter your ZIP code for your exact zone.

Q: What does zone 8b mean?

Zone 8b means the average annual extreme minimum temperature, the coldest night of a typical winter, is 15°F to 20°F (−9°C to −7°C). Perennials, shrubs and trees rated for zone 8b or colder should survive winter there.

Q: What is the coldest hardiness zone in Washington?

Zone 6a is the coldest zone mapped in Washington, found around Republic, and zone 9b is the warmest.

Q: Did Washington's hardiness zones change in 2023?

The USDA released a new Plant Hardiness Zone Map in November 2023, based on 1991–2020 temperatures instead of 1976–2005. About half of the United States shifted half a zone warmer. Check your ZIP code here, because plant tags and older books may still list your 2012 zone.

Q: When should I plant in zone 8b?

Hardiness zones don't set planting dates; frost dates do. Inside zone 8b in Washington, the median last spring frost varies from February 26 to May 1. Look up your local frost dates and plant tender crops such as tomatoes after the 10%-risk last-frost date.

USDA 2023 Plant Hardiness Zone Map · 708 ZIP codes · Data updated 2026-10-28

Quick answer

Washington spans USDA hardiness zones 6a–9b on the 2023 Plant Hardiness Zone Map. The most common zone is 8b, covering 37% of Washington's ZIP codes, followed by zone 9a (19%). Zone 8b means the coldest night of an average winter reaches 15°F to 20°F (−9°C to −7°C). Enter your ZIP code for your exact zone.

Washington hardiness zones by share of ZIP codes

Zone 6a2% · 17 ZIPs

Zone 6b12% · 88 ZIPs

Zone 7a18% · 125 ZIPs

Zone 7b4% · 30 ZIPs

Zone 8a7% · 47 ZIPs

Zone 8b37% · 263 ZIPs

Zone 9a19% · 137 ZIPs

Zone 9b<1% · 1 ZIP

What the zones mean for Washington gardeners

Coldest and warmest towns: among towns with NOAA weather stations, Republic (2,555 ft) is in zone 6a, while Grayland (10 ft) is in zone 9a. That is a difference of about 30°F in the coldest night of a typical winter.
Same zone, different frost dates: within zone 8b, the median last spring frost ranges from February 26 at Olga 2 SE to May 1 at Elma, 64 days apart. Your zone tells you which perennials survive winter; your frost dates tell you when to plant.

Typical frost dates in each Washington zone

Medians across NOAA weather stations in each zone. Colder zones usually have later spring frosts, but local terrain can shift the dates by weeks.

Zone	Last spring frost	First fall frost	Stations
6a	May 16	September 15	3
6b	May 8	September 30	18
7a	April 30	October 12	29
7b	April 17	October 22	9
8a	April 16	October 26	12
8b	April 8	November 2	37
9a	March 13	November 14	15

Hardiness zones for Washington cities

Zones at the National Weather Service stations, mostly city airports, with their median frost dates.


Bellingham Intl Airport	8a	10°F to 15°F	149	Mar 31	Oct 30
Deer Park Airport	6b	−5°F to 0°F	2,191	May 22	Sep 14
Ephrata Municipal Airport	6b	−5°F to 0°F	1,252	Apr 22	Oct 17
Everett Snohomish Airport	9a	20°F to 25°F	606	Mar 9	Nov 17
Friday Harbor Airport	9a	20°F to 25°F	109	Mar 26	Nov 10
Moses Lake Grant County Airport	7a	0°F to 5°F	1,196	Apr 27	Oct 8
Olympia Airport	8a	10°F to 15°F	188	Apr 29	Oct 14
Omak Airport	6b	−5°F to 0°F	1,296	Apr 30	Oct 7
Quillayute State Airport	9a	20°F to 25°F	185	Apr 20	Oct 26
Quinault 4 NE	8b	15°F to 20°F	286	Apr 7	Nov 10
Renton Municipal Airport	9a	20°F to 25°F	29	Mar 13	Nov 16
Seattle Boeing Field	9a	20°F to 25°F	20	Mar 13	Nov 17
Seattle Sand Point Wsfo	9a	20°F to 25°F	60	Mar 8	Nov 23
Seattle Tacoma Intl Airport	9a	20°F to 25°F	370	Mar 2	Nov 23
Shelton Sanderson Field	8b	15°F to 20°F	271	Apr 27	Oct 16
Spokane 17 SSW	6b	−5°F to 0°F	2,267	May 30	Sep 4
Spokane Felts Field	7a	0°F to 5°F	1,953	Apr 26	Oct 15
Spokane Intl Airport	6b	−5°F to 0°F	2,353	Apr 26	Oct 12
Stampede Pass	7a	0°F to 5°F	3,959	May 14	Oct 17
Tacoma Narrows Airport	9a	20°F to 25°F	292	Mar 11	Nov 21
The Dalles Municipal Airport	8a	10°F to 15°F	235	Apr 11	Oct 26
Toledo Faa Airport	8a	10°F to 15°F	379	Apr 5	Oct 25
Vancouver Pearson Airport	8b	15°F to 20°F	30	Mar 29	Nov 9
Walla Walla Regional Airport	7a	0°F to 5°F	1,166	Mar 27	Oct 31
Wenatchee Pangborn Airport	7a	0°F to 5°F	1,229	Apr 8	Oct 24
Whidbey Island NAS	8b	15°F to 20°F	47	Mar 13	Nov 14

Hardiness zones for 125 towns in Washington

Each NOAA weather station is shown with the USDA zone of the nearest ZIP code (within 8 miles). Coldest night is the zone's range for the average annual extreme minimum temperature. Click a column to sort.

Filter by town


Aberdeen	8b	15°F to 20°F	10	Mar 29	Nov 15
Aberdeen 20NNE	8b	15°F to 20°F	435	Apr 15	Nov 2
Anacortes	8b	15°F to 20°F	20	Mar 8	Nov 20
Baring	8a	10°F to 15°F	770	Apr 14	Oct 29
Battle Ground	8b	15°F to 20°F	284	Apr 26	Oct 16
Bellingham 3 SSW	8b	15°F to 20°F	15	Apr 1	Nov 2
Bellingham Intl Airport	8a	10°F to 15°F	149	Mar 31	Oct 30
Bickleton	7b	5°F to 10°F	3,015	May 16	Oct 9
Blaine	8b	15°F to 20°F	60	Mar 31	Nov 4
Bremerton	9a	20°F to 25°F	110	Mar 29	Nov 14
Buckley 1 NE	8b	15°F to 20°F	685	Apr 7	Oct 30
Carson Fish Hatchery	8a	10°F to 15°F	1,134	May 2	Oct 9
Cedar Lake	8a	10°F to 15°F	1,560	Apr 23	Nov 1
Centralia	8b	15°F to 20°F	185	Apr 22	Oct 27
Chelan	7b	5°F to 10°F	1,194	Apr 17	Oct 22
Chewelah	6a	−10°F to −5°F	1,670	May 16	Sep 15
Chief Joseph Dam	7a	0°F to 5°F	834	Apr 26	Oct 11
Cle Elum	7a	0°F to 5°F	1,900	May 13	Sep 25
Clearbrook	8a	10°F to 15°F	64	Apr 18	Oct 18
Concrete Ppl Fish Station	8a	10°F to 15°F	195	Mar 28	Nov 14
Connell 1 W	7a	0°F to 5°F	1,020	Apr 30	Oct 12
Cougar 6 E	8a	10°F to 15°F	659	Apr 1	Nov 18
Coulee Dam 1 SW	7b	5°F to 10°F	1,719	Apr 22	Oct 21
Coupeville 1 S	8b	15°F to 20°F	50	Mar 17	Nov 11
Cushman Powerhouse #2	8b	15°F to 20°F	21	Mar 24	Nov 15
Davenport	6b	−5°F to 0°F	2,369	Jun 6	Sep 11
Dayton 1 WSW	7a	0°F to 5°F	1,557	Apr 28	Oct 13
Deer Park Airport	6b	−5°F to 0°F	2,191	May 22	Sep 14
Ellensburg	6b	−5°F to 0°F	1,480	May 8	Oct 2
Elma	8b	15°F to 20°F	70	May 1	Oct 14
Entiat Fish Hatchery	7a	0°F to 5°F	1,027	Apr 5	Oct 24
Ephrata Municipal Airport	6b	−5°F to 0°F	1,252	Apr 22	Oct 17
Everett	8b	15°F to 20°F	60	Mar 24	Nov 2
Everett Snohomish Airport	9a	20°F to 25°F	606	Mar 9	Nov 17
Forks 1 E	8b	15°F to 20°F	350	Apr 26	Oct 25
Friday Harbor Airport	9a	20°F to 25°F	109	Mar 26	Nov 10
Glenoma	8a	10°F to 15°F	840	Apr 24	Oct 15
Glenwood #2	7a	0°F to 5°F	1,902	Any month	Any month
Goldendale	7a	0°F to 5°F	1,640	May 19	Sep 25
Grayland	9a	20°F to 25°F	10	Mar 29	Nov 7
Grays River Hatchery	8b	15°F to 20°F	100	Apr 27	Oct 22
Harrington	6b	−5°F to 0°F	2,159	May 31	Sep 12
Hartline	6b	−5°F to 0°F	1,906	May 2	Oct 12
Humptulips Salmon Hatchery	9a	20°F to 25°F	140	Apr 26	Oct 22
Ice Harbor Dam	7a	0°F to 5°F	368	Apr 7	Oct 22
Kennewick	7b	5°F to 10°F	390	Mar 28	Oct 30
Kent	9a	20°F to 25°F	30	Mar 20	Nov 10
Lacrosse	7a	0°F to 5°F	1,476	May 13	Sep 26
Landsburg	8b	15°F to 20°F	535	Apr 20	Oct 25
Leavenworth 3 S	7a	0°F to 5°F	1,128	May 10	Sep 30
Lind 3 NE	7a	0°F to 5°F	1,630	May 7	Oct 4
Long Beach Experiment Station	9a	20°F to 25°F	25	Apr 6	Oct 26
Longview	8b	15°F to 20°F	12	Apr 8	Nov 5
Mayfield Pwr Plt	8b	15°F to 20°F	280	Apr 7	Nov 13
McMillin Rsvr	8b	15°F to 20°F	579	Apr 11	Oct 30
McNary Dam	7b	5°F to 10°F	361	Mar 27	Nov 4
Methow 2 S	7a	0°F to 5°F	1,135	Apr 21	Oct 15
Monroe	8b	15°F to 20°F	120	Apr 17	Oct 23
Moses Lake Grant County Airport	7a	0°F to 5°F	1,196	Apr 27	Oct 8
Mount Adams Ranger Station	7a	0°F to 5°F	1,950	May 18	Sep 25
Mount Vernon 3 WNW	8b	15°F to 20°F	14	Mar 24	Nov 3
Moxee City 10 E	7a	0°F to 5°F	1,550	May 4	Oct 10
Mud Mountain Dam	8b	15°F to 20°F	1,308	Apr 18	Oct 31
Naselle 2 ENE	8b	15°F to 20°F	50	Apr 24	Oct 20
Newport	6a	−10°F to −5°F	2,162	May 12	Sep 21
Northport	6b	−5°F to 0°F	1,497	May 8	Oct 1
Odessa	6b	−5°F to 0°F	1,543	May 14	Sep 26
Olga 2 SE	8b	15°F to 20°F	80	Feb 26	Nov 29
Olympia Airport	8a	10°F to 15°F	188	Apr 29	Oct 14
Omak Airport	6b	−5°F to 0°F	1,296	Apr 30	Oct 7
Palmer 3 ESE	8b	15°F to 20°F	920	Apr 3	Nov 11
Pomeroy	7a	0°F to 5°F	1,934	May 2	Oct 4
Port Angeles	8b	15°F to 20°F	90	Mar 12	Nov 19
Port Townsend	9a	20°F to 25°F	100	Mar 1	Nov 28
Prosser	7b	5°F to 10°F	830	Apr 14	Oct 22
Pullman 2 NW	6b	−5°F to 0°F	2,515	May 6	Sep 29
Quilcene 2 SW	8b	15°F to 20°F	123	Apr 11	Oct 28
Quillayute State Airport	9a	20°F to 25°F	185	Apr 20	Oct 26
Quinault 4 NE	8b	15°F to 20°F	286	Apr 7	Nov 10
Quincy	7a	0°F to 5°F	1,286	Apr 21	Oct 16
Rainier Paradise Ranger Station	7a	0°F to 5°F	5,427	Any month	Any month
Raymond 2 S	8a	10°F to 15°F	30	Apr 26	Oct 17
Renton Municipal Airport	9a	20°F to 25°F	29	Mar 13	Nov 16
Republic	6a	−10°F to −5°F	2,555	May 30	Sep 10
Richland	7b	5°F to 10°F	373	Apr 6	Oct 24
Ritzville 1 SSE	6b	−5°F to 0°F	1,864	May 7	Oct 10
Rosalia	6b	−5°F to 0°F	2,420	May 7	Sep 28
Sagemoor	7a	0°F to 5°F	595	Apr 30	Oct 13
Seattle Boeing Field	9a	20°F to 25°F	20	Mar 13	Nov 17
Seattle Sand Point Wsfo	9a	20°F to 25°F	60	Mar 8	Nov 23
Seattle Tacoma Intl Airport	9a	20°F to 25°F	370	Mar 2	Nov 23
Sedro-woolley	8b	15°F to 20°F	60	Mar 27	Nov 6
Selah 2 NE	7a	0°F to 5°F	1,120	May 5	Oct 4
Sequim 2 E	8b	15°F to 20°F	50	Apr 21	Oct 20
Shelton Sanderson Field	8b	15°F to 20°F	271	Apr 27	Oct 16
Skamania Fish Hatchery	8b	15°F to 20°F	435	Apr 29	Oct 22
Smyrna	7a	0°F to 5°F	560	Apr 23	Oct 12
Snoqualmie Falls	8b	15°F to 20°F	440	Mar 30	Nov 7
Snowden	7a	0°F to 5°F	2,415	May 12	Oct 11
Spokane 17 SSW	6b	−5°F to 0°F	2,267	May 30	Sep 4
Spokane Felts Field	7a	0°F to 5°F	1,953	Apr 26	Oct 15
Spokane Intl Airport	6b	−5°F to 0°F	2,353	Apr 26	Oct 12
Spokane WFO	6b	−5°F to 0°F	2,392	May 10	Sep 26
St John	6b	−5°F to 0°F	1,952	Apr 29	Oct 4
Stampede Pass	7a	0°F to 5°F	3,959	May 14	Oct 17
Startup 1 E	8b	15°F to 20°F	170	Apr 15	Oct 25
Stehekin 4 NW	6b	−5°F to 0°F	1,257	Apr 27	Oct 17
Sunnyside	7b	5°F to 10°F	747	May 1	Oct 6
Sunnyside #2	7b	5°F to 10°F	805	Apr 30	Oct 8
Tacoma #1	9a	20°F to 25°F	25	Mar 8	Nov 14
Tacoma Narrows Airport	9a	20°F to 25°F	292	Mar 11	Nov 21
The Dalles Municipal Airport	8a	10°F to 15°F	235	Apr 11	Oct 26
Toledo Faa Airport	8a	10°F to 15°F	379	Apr 5	Oct 25
Tolt S Fk Rsvr	8b	15°F to 20°F	2,000	Apr 13	Nov 10
Vancouver 4 NNE	8b	15°F to 20°F	210	Apr 26	Oct 18
Vancouver Pearson Airport	8b	15°F to 20°F	30	Mar 29	Nov 9
Walla Walla Regional Airport	7a	0°F to 5°F	1,166	Mar 27	Oct 31
Wapato	7a	0°F to 5°F	841	Apr 21	Oct 15
Waterville	7a	0°F to 5°F	2,664	May 14	Oct 1
Wenatchee	7a	0°F to 5°F	626	Apr 4	Oct 28
Wenatchee Pangborn Airport	7a	0°F to 5°F	1,229	Apr 8	Oct 24
Whidbey Island NAS	8b	15°F to 20°F	47	Mar 13	Nov 14
Whitman Mission	7a	0°F to 5°F	632	May 2	Oct 1
Wilbur	6b	−5°F to 0°F	2,262	Jun 1	Sep 22
Yakima #2	7a	0°F to 5°F	1,142	Apr 8	Oct 23

Frequently asked questions

What hardiness zone is Washington?

Washington is in USDA hardiness zones 6a–9b on the 2023 USDA Plant Hardiness Zone Map. Zone 8b is the most common, covering 37% of Washington's ZIP codes, and zone 9a covers 19%. Enter your ZIP code for your exact zone.

What does zone 8b mean?

Zone 8b means the average annual extreme minimum temperature, the coldest night of a typical winter, is 15°F to 20°F (−9°C to −7°C). Perennials, shrubs and trees rated for zone 8b or colder should survive winter there.

What is the coldest hardiness zone in Washington?

Zone 6a is the coldest zone mapped in Washington, found around Republic, and zone 9b is the warmest.

Did Washington's hardiness zones change in 2023?

The USDA released a new Plant Hardiness Zone Map in November 2023, based on 1991–2020 temperatures instead of 1976–2005. About half of the United States shifted half a zone warmer. Check your ZIP code here, because plant tags and older books may still list your 2012 zone.

When should I plant in zone 8b?

Hardiness zones don't set planting dates; frost dates do. Inside zone 8b in Washington, the median last spring frost varies from February 26 to May 1. Look up your local frost dates and plant tender crops such as tomatoes after the 10%-risk last-frost date.

Zone and frost dates: use both

Your hardiness zone answers one question: will this plant survive the winter here? Choose perennials, shrubs, trees and bulbs rated for your zone or a colder one. For vegetables and annuals, what matters is the length of the frost-free season. See Washington frost dates by town, or get a planting calendar for your ZIP code with start-indoors, transplant and sowing dates for 30 crops.

Sources and method

Zones are from the USDA 2023 Plant Hardiness Zone Map ZIP-code files published by the PRISM Climate Group, Oregon State University, based on 1991–2020 minimum temperatures. ZIP codes are assigned to states by USPS prefix. Town zones use the ZIP code nearest each NOAA 1991–2020 Climate Normals station. This is an independent tool, not an official USDA site. Full methodology.