Frost dates · USDA zone 9a
Frost dates for Burien, WA
Burien, WA sees its last 32 °F night of spring around March 2 and its first of fall around November 23 — a 266-day freeze-free season in a typical year.
Pick a sauce; the Plan Builder runs this station's dates and hands back the calendar, plant count and gear list.
Freeze odds, by date
| Odds | Last spring freeze after | First fall freeze before |
|---|---|---|
| 9 years in 10 | Feb 5 | Dec 15 |
| Median — 1 year in 2 | Mar 2 | Nov 23 |
| 1 year in 10 | Mar 23 | Nov 6 |
The top row is the risky edge: in 9 years of 10 a spring freeze still comes after it, so tender transplants set out then need cover. The bottom row is the cautious date — only 1 year in 10 freezes after it — and the one to plan uncovered tender transplants against. Freeze-free season: 266 days median, at least 239 in 9 years of 10, at least 298 days in 1 year of 10. NOAA ranks season length year by year, so it is not the gap between two rows above. A hard freeze (28 °F) has a median last date of Feb 4 and first of Dec 10.
Burien planting calendar, 2027
Every row runs from the median last frost (Mar 2) and median first frost (Nov 23) above, using each cultivar's days to maturity. Same engine as the Plan Builder.
| Crop | Start indoors | Transplant / plant | First harvest | Days |
|---|---|---|---|---|
| Hardneck GarlicSiberian (porcelain hardneck) | — | Oct 15prior fall | Jun 12 | 240 from sow |
| Spanish OnionYellow Sweet Spanish (long-day) | Dec 8 | Feb 2 | May 23 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Mar 2 | Apr 1 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Feb 16 | Feb 16 | Apr 2 | 45 from sow |
| Genovese BasilGenovese | Feb 2 | Mar 16 | May 15 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Jan 5 | Mar 9 | May 23 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Dec 22 | Mar 16 | Jun 19 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Jan 5 | Mar 9 | May 23 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Jan 5 | Mar 9 | May 28 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Jan 5 | Mar 9 | May 28 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Feb 16 | Feb 16 | Apr 27 | 70 from sow |
| TomatilloToma Verde | Jan 19 | Mar 9 | May 18 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Jan 19 | Mar 9 | May 23 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Jan 19 | Mar 9 | May 28 | 80 from transplant |
Tight means first harvest lands within two weeks of the median first fall frost: start that crop indoors on time or cover it in fall.
What sauce can Burien grow?
Each sauce, scheduled for a Burien container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Burien frost questions
When is the last frost in Burien, WA?
The median last 32 °F freeze at SEATTLE TACOMA INTL AP, WA is March 2: half of years see a later one. One year in ten, a freeze still comes after March 23; nine years in ten, it comes after February 5. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Burien, WA?
The median first 32 °F freeze of fall is November 23. One year in ten it arrives before November 6; nine years in ten, before December 15.
How long is the growing season in Burien, WA?
266 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 239 days; one year in ten, at least 298 days.
What growing zone is Burien, WA?
USDA hardiness zone 9a, per the 2023 USDA Plant Hardiness Zone Map for ZIP 98166. A zone describes the coldest winter night, not when frost ends, so it is the wrong number for a planting calendar — the frost dates on this page are the right one.
When should I plant tomatoes in Burien, WA?
Start Roma VF (determinate paste) seeds indoors around Jan 19 and transplant around Mar 9, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for Mar 23. First ripe fruit lands around May 23.
When should I plant peppers in Burien, WA?
Sow jalapeño indoors on a heat mat around Jan 5; transplant no earlier than Mar 9, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around May 23.
Nearby in Washington
- Rentonlast frost Mar 13
- Kentlast frost Mar 20
- Seattlelast frost Mar 13
- Federal Waylast frost Mar 8
- Bellevuelast frost Mar 8
- Auburnlast frost Mar 20
All Washington frost dates → · How frost-date math drives a sowing calendar →