When to plant in Union Hill-Novelty Hill, WA
USDA Zone 8bEverything below — frost dates, hardiness zone, and what to plant when in Union Hill-Novelty Hill, Washington — is derived from the closest NOAA station with complete climate normals.
A generous ~260-day season lets Union Hill-Novelty Hill gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Union Hill-Novelty Hill's nearest full-normals station sits about 17 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. In zone 8b, Union Hill-Novelty Hill supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
SEATTLE SAND PT WSFO · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Union Hill-Novelty Hill’s own odds, recorded at SEATTLE SAND PT WSFO.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 26 | Apr 4 | Mar 17 | Oct 24 | Nov 5 | Nov 22 |
| 32°F | Mar 29 | Mar 8 | Feb 13 | Nov 4 | Nov 23 | Dec 16 |
| 28°F | Mar 1 | Feb 11 | Dec 27 | Nov 17 | Dec 11 | Jan 17 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Union Hill-Novelty Hill, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 21 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Union Hill-Novelty Hill planting FAQ
When is the last spring frost in Union Hill-Novelty Hill, WA?
Plan for the last spring frost in Union Hill-Novelty Hill around March 8 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Union Hill-Novelty Hill, WA?
In Union Hill-Novelty Hill, the first 32°F freeze of fall lands around November 23 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Union Hill-Novelty Hill in?
Union Hill-Novelty Hill is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.
How long is the growing season in Union Hill-Novelty Hill?
Union Hill-Novelty Hill has about 260 frost-free days — a long growing season — between the average last spring frost (March 8) and first fall frost (November 23).
When should I plant tomatoes in Union Hill-Novelty Hill?
For Union Hill-Novelty Hill, sow tomatoes indoors about January 11–January 25 and move the seedlings out around March 15, after the last spring frost.
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Nearby cities
8 within reach- Redmond · 7 km
- Cottage Lake · 8 km
- Sammamish · 10 km
- Woodinville · 13 km
- Kirkland · 14 km
- Bellevue · 14 km
- Maltby · 15 km
- Issaquah · 15 km
Frost dates recorded at SEATTLE SAND PT WSFO, 17 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Union Hill-Novelty Hill, WA — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094290. Retrieved from https://blissgarden.com/washington/union-hill-novelty-hill.