Arlington, WA planting zone & frost dates

Arlington is in USDA hardiness zone 8a. The last spring frost usually comes around April 22 and the first fall frost around October 19, for a growing season of about 181 days.

USDA hardiness zone8aavg. extreme winter low 10°F to 15°F
Average last spring frostApril 2290% chance of no frost after May 6
Average first fall frostOctober 1910% chance of frost by October 3
Growing season181 daysfrost-free days in an average year

Planting calendar for Arlington

Dates are counted from the average last spring frost (April 22) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.

CropWhen
TomatoesStart seeds indoors: Feb 25 – Mar 11
Transplant outdoors: Apr 29 – May 6
PeppersStart seeds indoors: Feb 11 – Feb 25
Transplant outdoors: May 6 – May 13
EggplantStart seeds indoors: Feb 11 – Feb 25
Transplant outdoors: May 6 – May 13
BroccoliStart seeds indoors: Feb 11 – Feb 25
Transplant outdoors: Mar 25 – Apr 8
CabbageStart seeds indoors: Feb 11 – Feb 25
Transplant outdoors: Mar 25 – Apr 8
Onions (sets)Plant outdoors: Mar 25 – Apr 8
PeasSow outdoors: Mar 11 – Mar 25
SpinachSow outdoors: Mar 11 – Mar 25
LettuceSow outdoors: Mar 25 – Apr 8
CarrotsSow outdoors: Mar 25 – Apr 8
PotatoesPlant outdoors: Mar 25 – Apr 8
BeansSow outdoors: Apr 29 – May 6
Sweet cornSow outdoors: Apr 29 – May 6
CucumbersSow outdoors: Apr 29 – May 6
Squash & zucchiniSow outdoors: Apr 29 – May 6
BasilStart seeds indoors: Mar 11 – Mar 25
Transplant outdoors: Apr 29 – May 6

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 24 (8 weeks before the average first fall frost on Oct 19).

Useful for zone 8a gardens

As an Amazon Associate, FrostZoneMap earns from qualifying purchases, at no extra cost to you.

Frost risk in detail

90% chance50% chance10% chance
Last 32°F frost in spring is afterApr 4Apr 22May 6
First 32°F frost in fall is beforeNov 4Oct 19Oct 3

How to read it: in spring there is a 10% chance of a frost after May 6, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 3. A hard freeze (28°F) usually ends around March 25.

Hardiness zone by ZIP code in Arlington

Nearby cities

All cities in Washington → · Other zone 8a cities →

Questions

What growing zone is Arlington, WA?

Arlington is in USDA Plant Hardiness Zone 8a (average extreme winter low 10°F to 15°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 8b.

When is the last frost in Arlington?

The average last spring frost (32°F) in Arlington is April 22. There is still a 10% chance of frost until May 6.

When can I plant tomatoes in Arlington?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 29 – May 6. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Arlington, WA (USC00450257), 0.3 km (0.2 mi) from the city center, elevation 30 m, based on 5 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.