US Grow Zones

Federal Way, Washington: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USC00458278); U.S. Census Bureau — see methodology

Federal Way is in USDA plant hardiness zone 8b, where the average coldest winter night reaches 15 to 20°F (-9.4 to -6.7°C). The typical last spring frost is around Mar 17 and the first fall frost around Nov 7.

Hardiness zone8B15 to 20°F
Last spring frostMar 1730% chance of frost after
First fall frostNov 730% chance of frost before
Growing season250 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)Mar 31Oct 30
Typical planning date (30% risk)Mar 17Nov 7
Median (50%)Mar 8Nov 14

How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.

Frost data comes from NOAA station TACOMA #1, WA (USC00458278), 5.7 mi (9.1 km) from the city center and 371 ft lower than the city center (-113 m). Record used for the 1991–2020 normals: 26 years.

Frost probability in spring and fall, Federal Way, WAChance of a 32°F frost in Federal Way, WA, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Feb 15 to 10% on Mar 31. Fall: the chance that the first frost has arrived rises from 10% on Oct 30 to 90% on Dec 2.0%50%100%Spring: later frostJan 1Feb 1Mar 1Apr 130%: Mar 17Fall: frost arrivedNov 1Dec 1Jan 130%: Nov 732°F frost28°F hard freezeplanning date
Shaded areas show the chance of a 32°F frost: falling through spring, rising through fall. The dashed line is the 28°F hard-freeze curve. Data: NOAA 1991–2020 Normals, station USC00458278.
Frost-free growing season in Federal Way, WA1 in 10 risk: Mar 31 to Oct 30 (213 days); 3 in 10 risk: Mar 17 to Nov 7 (235 days); Median (50%): Mar 8 to Nov 14 (251 days); No 28°F freeze: Feb 11 to Dec 1 (293 days). In 9 of 10 years the 32°F-free season is at least 223 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk213 days3 in 10 risk235 daysMedian (50%)251 daysNo 28°F freeze293 days
Frost-free window at three risk levels, plus the window between 28°F hard freezes. Read about what the probabilities mean.

Why your yard may differ from the station: microclimates.

Hardiness zone across Federal Way

All 3 ZIP codes covering Federal Way are in zone 8b.

ZIP codes in Federal Way and their zones
ZIPZoneShare of city land
980038b46.1%
980238b46.0%
980018b7.3%

Vegetable planting calendar for Federal Way

Dates are counted from the 30%-risk frost dates above (last frost Mar 17, first frost Nov 7). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoJan 20 – Feb 3Mar 24 – Apr 7——
PepperJan 6 – Jan 20Mar 31 – Apr 14——
LettuceFeb 3 – Feb 17Mar 3 – Mar 24Feb 17 – Mar 31Aug 29 – Sep 26
Green Beans——Mar 24 – Apr 28Aug 15 – Aug 29
Sweet Corn——Mar 24 – Apr 21—
Zucchini & Summer SquashFeb 17 – Feb 24Mar 24 – Apr 7Mar 24 – Apr 14Aug 15 – Aug 29
CucumberFeb 17 – Feb 24Mar 31 – Apr 7Mar 24 – Apr 14Aug 15 – Aug 29
Carrot——Feb 24 – Mar 31Aug 15 – Aug 29
OnionDec 23 – Jan 6Feb 17 – Mar 3——
Potato—Feb 17 – Mar 10——
BasilFeb 3 – Feb 17Mar 31 – Apr 14Mar 31 – Apr 21—
Spinach——Feb 3 – Mar 3Sep 12 – Oct 10
KaleJan 20 – Feb 3Feb 17 – Mar 10Feb 17 – Mar 10Aug 29 – Sep 26
BroccoliJan 20 – Feb 3Mar 3 – Mar 24—Aug 15 – Aug 29
Peas——Feb 3 – Feb 24Aug 29 – Sep 12
EggplantJan 6 – Jan 20Mar 31 – Apr 14——
CabbageJan 20 – Feb 3Feb 17 – Mar 3—Aug 15 – Aug 29
Radish——Feb 10 – Mar 31Sep 26 – Oct 24
Strawberry—Feb 17 – Mar 10——
Beets——Feb 24 – Apr 7Aug 29 – Sep 12

Nearby cities in Washington

More: all Washington cities · other zone 8b cities: Dallas, TX, Fort Worth, TX, El Paso, TX, Virginia Beach, VA, Arlington, TX, Plano, TX, Irving, TX, Garland, TX

Federal Way gardening questions

When is the last frost in Federal Way, WA?

Plan around Mar 17. At NOAA's Tacoma #1, WA station, 5.7 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Mar 8, and after Mar 31 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Feb 11. The 90% and 10% dates are 44 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Federal Way, WA?

Start seeds indoors Jan 20 – Feb 3 and set transplants outside Mar 24 – Apr 7, once nights stay above 50°F and the soil is near 60°F. That leaves 235 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.

How long is the growing season in Federal Way?

About 250 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 223 days, and in 1 year in 10 it runs 283 days or more. In fall there is a 10% chance of frost by Oct 30 and a 30% chance by Nov 7. That ranks 6th longest of 18 Washington cities on this site.

When should I plant a fall garden in Federal Way?

Count back from the first fall frost (Nov 7): transplant broccoli Aug 15 – Aug 29; sow kale Aug 29 – Sep 26; sow lettuce Aug 29 – Sep 26; sow radishes Sep 26 – Oct 24. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Dec 1. How the math works: succession and fall planting.

Did Federal Way's hardiness zone change on the 2023 map?

No. Going by the zone that covers most of the city's land, Federal Way is zone 8b on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.

How does Federal Way compare with Auburn, WA?

Both are in zone 8b. The typical last spring frost in Federal Way (Mar 17) comes about 12 days earlier than in Auburn, WA (Mar 29), 6 miles away, and the first fall frost is Nov 7 versus Nov 3. Federal Way sits about 298 ft higher, which explains part of the gap. The two cities use different NOAA stations.