Frost dates · USDA zone 8b
Frost dates for Sammamish, WA
Sammamish, WA sees its last 32 °F night of spring around March 30 and its first of fall around November 7 — a 223-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 | Mar 4 | Dec 1 |
| Median — 1 year in 2 | Mar 30 | Nov 7 |
| 1 year in 10 | Apr 21 | Oct 22 |
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: 223 days median, at least 195 in 9 years of 10, at least 252 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 27 and first of Nov 29.
Sammamish planting calendar, 2027
Every row runs from the median last frost (Mar 30) and median first frost (Nov 7) 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) | Jan 5 | Mar 2 | Jun 20 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Mar 30 | Apr 29 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Mar 16 | Mar 16 | Apr 30 | 45 from sow |
| Genovese BasilGenovese | Mar 2 | Apr 13 | Jun 12 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Feb 2 | Apr 6 | Jun 20 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Jan 19 | Apr 13 | Jul 17 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Feb 2 | Apr 6 | Jun 20 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Feb 2 | Apr 6 | Jun 25 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Feb 2 | Apr 6 | Jun 25 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Mar 16 | Mar 16 | May 25 | 70 from sow |
| TomatilloToma Verde | Feb 16 | Apr 6 | Jun 15 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Feb 16 | Apr 6 | Jun 20 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Feb 16 | Apr 6 | Jun 25 | 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 Sammamish grow?
Each sauce, scheduled for a Sammamish container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Sammamish frost questions
When is the last frost in Sammamish, WA?
The median last 32 °F freeze at SNOQUALMIE FALLS, WA is March 30: half of years see a later one. One year in ten, a freeze still comes after April 21; nine years in ten, it comes after March 4. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Sammamish, WA?
The median first 32 °F freeze of fall is November 7. One year in ten it arrives before October 22; nine years in ten, before December 1.
How long is the growing season in Sammamish, WA?
223 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 195 days; one year in ten, at least 252 days.
What growing zone is Sammamish, WA?
USDA hardiness zone 8b, per the 2023 USDA Plant Hardiness Zone Map for ZIP 98075. 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 Sammamish, WA?
Start Roma VF (determinate paste) seeds indoors around Feb 16 and transplant around Apr 6, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for Apr 21. First ripe fruit lands around Jun 20.
When should I plant peppers in Sammamish, WA?
Sow jalapeño indoors on a heat mat around Feb 2; transplant no earlier than Apr 6, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Jun 20.
Nearby in Washington
- Bellevuelast frost Mar 8
- Redmondlast frost Mar 8
- Kirklandlast frost Mar 8
- Rentonlast frost Mar 13
- Bothelllast frost Mar 8
- Seattlelast frost Mar 13
All Washington frost dates → · How frost-date math drives a sowing calendar →