Fall in zone 8bPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 98010 (Black Diamond, WA)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Landsburg, WA (5 miles away).
- Average last spring frostApr 2050% chance of a 32°F freeze after this date
- Average first fall frostOct 2550% chance of a 32°F freeze by this date
- Growing season (frost-free)187 daysmedian, 32°F threshold
- USDA hardiness zone8b15 to 20°F avg. coldest night
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
No soil station with a fresh reading within 62 miles.
4-inch depth
No soil station with a fresh reading within 62 miles.
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 98010 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
No soil reading near this ZIP. Typical extension timing for your region: spring March to April.
Fertilizer window
Lawn region: Pacific Northwest (west of the Cascades). Timing only; always follow the product label.
- Perennial ryegrass (cool-season): Early fall: September; Late fall: October–November; Overseeded Bermuda: Light feeding once the winter rye is established, if needed. Avoid: Summer feeding.
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Oct 25: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Mar 31 |
| 50% (the "average" last frost) | Apr 20 |
| 10% (cautious: only 1 year in 10 freezes later) | May 10 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Oct 5 |
| 50% (the "average" first frost) | Oct 25 |
| 90% (late: most years have frozen by now) | Nov 12 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 10 | Oct 6 |
| 32°F (freeze) | Apr 20 | Oct 25 |
| 28°F (hard freeze) | Mar 24 | Nov 12 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 98010
Dates count from your average last spring frost (Apr 20) and first fall frost (Oct 25). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Feb 23–Mar 9 | Apr 27–May 11 (transplant) | – |
| Pepper (sweet and hot) | Feb 9–23 | May 4–18 (transplant) | – |
| Eggplant | Feb 9–23 | May 4–18 (transplant) | – |
| Tomatillo | Feb 23–Mar 9 | Apr 27–May 11 (transplant) | – |
| Lettuce | Feb 23–Mar 9 | Mar 30–Apr 20 (transplant) Mar 23–May 4 (sow outdoors) | Aug 30–Sep 20 (transplant) Aug 16–Sep 13 (sowing) |
| Spinach | – | Mar 9–30 (sow outdoors) | Aug 30–Sep 20 (sowing) |
| Kale | Feb 23–Mar 9 | Mar 23–Apr 6 (transplant) Mar 23–Apr 6 (sow outdoors) | Aug 2–30 (transplant) Jul 19–Aug 16 (sowing) |
| Collards | Feb 23–Mar 9 | Mar 23–Apr 20 (transplant) Mar 23–Apr 20 (sow outdoors) | Aug 2–30 (transplant) Jul 19–Aug 16 (sowing) |
| Broccoli | Feb 9–23 | Mar 23–Apr 6 (transplant) | Jul 19–Aug 16 (transplant) |
| Cabbage | Feb 9–23 | Mar 23–Apr 6 (transplant) | Jul 19–Aug 16 (transplant) |
| Cauliflower | Feb 9–23 | Apr 6–20 (transplant) | Jul 19–Aug 16 (transplant) |
| Brussels sprouts | Jan 26–Feb 9 | Mar 23–Apr 6 (transplant) | Jul 5–26 (transplant) |
| Kohlrabi | Feb 23–Mar 9 | Mar 23–Apr 6 (transplant) Mar 23–Apr 6 (sow outdoors) | Aug 16–30 (sowing) |
| Bok choy / Asian greens | – | Mar 23–Apr 6 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Arugula | – | Mar 23–Apr 20 (sow outdoors) | Aug 30–Sep 27 (sowing) |
| Mustard greens | – | Mar 23–Apr 13 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Swiss chard | Mar 9–23 | Apr 6–27 (transplant) Apr 6–May 4 (sow outdoors) | Aug 16–30 (sowing) |
| Beet | – | Mar 23–Apr 20 (sow outdoors) | Aug 16–30 (sowing) |
| Carrot | – | Mar 30–Apr 27 (sow outdoors) | Aug 2–16 (sowing) |
| Radish | – | Mar 16–Apr 27 (sow outdoors) | Sep 13–27 (sowing) |
| Turnip | – | Mar 23–Apr 13 (sow outdoors) | Aug 16–30 (sowing) |
| Parsnip | – | Mar 30–Apr 20 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 23–Mar 23 (sow outdoors) | Aug 2–16 (sowing) |
| Onion (bulbing) | Jan 26–Feb 9 | Mar 9–23 (transplant) | – |
| Green onion / scallion | – | Mar 9–Apr 6 (sow outdoors) | Aug 16–30 (sowing) |
| Leek | Jan 26–Feb 9 | Mar 23–Apr 6 (transplant) | – |
| Garlic | – | – | Sep 13–Oct 11 (sowing) |
| Shallot | – | Mar 9–23 (transplant) | Sep 13–Oct 11 (sowing) |
| Potato | – | Mar 23–Apr 6 (transplant) | Jul 5–19 (transplant) |
| Sweet potato | – | May 11–25 (transplant) | – |
| Sweet corn | – | Apr 27–May 11 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 27–May 11 (sow outdoors) | – |
| Bean, pole | – | Apr 27–May 11 (sow outdoors) | – |
| Lima bean | – | May 4–18 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 11–Jun 1 (sow outdoors) | – |
| Cucumber | Mar 23–30 | Apr 27–May 11 (transplant) Apr 27–May 11 (sow outdoors) | – |
| Summer squash / zucchini | Mar 23–30 | Apr 27–May 11 (transplant) Apr 27–May 11 (sow outdoors) | – |
| Winter squash | Mar 23–30 | Apr 27–May 11 (transplant) Apr 27–May 11 (sow outdoors) | – |
| Pumpkin | – | Apr 27–May 11 (sow outdoors) | – |
| Watermelon | Mar 23–30 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 23–30 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Okra | Mar 9–23 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Celery | Jan 26–Feb 9 | Apr 27–May 4 (transplant) | – |
| Basil | Mar 9–23 | Apr 27–May 11 (transplant) Apr 27–May 11 (sow outdoors) | – |
| Cilantro | – | Apr 6–May 4 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Parsley | Feb 9–23 | Apr 6–20 (transplant) Mar 30–Apr 20 (sow outdoors) | – |
| Dill | – | Apr 20–May 4 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Sunflower | – | Apr 20–May 4 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 23–Apr 6 (transplant) | – |
| Rhubarb (crowns) | – | Mar 23–Apr 6 (transplant) | – |
| Strawberry (plants) | – | Mar 23–Apr 6 (transplant) | Aug 16–Sep 13 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Landsburg, WA (NOAA GHCN-Daily ID USC00454486), elevation 535 ft, 4.6 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Palmer 3 ESE, WA | 7 mi | Apr 3 | Nov 11 |
| Buckley 1 NE, WA | 10 mi | Apr 7 | Oct 30 |
| Mud Mtn Dam, WA | 12 mi | Apr 18 | Oct 31 |
The average last-frost dates of these stations span 17 days, a rough guide to local variation. See data sources & methods.
Frost questions for 98010
When is the last frost in 98010?
The average (50% chance) last spring freeze of 32°F for ZIP 98010 is April 20. For a more cautious planting date, use May 10, when only 1 year in 10 still sees a later freeze.
When is the first frost in 98010?
The average first fall freeze is October 25. In 1 year in 10 it comes by October 5.
What hardiness zone is 98010?
ZIP 98010 is in USDA zone 8b (15 to 20°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 98010 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
98051 Ravensdale 98092 Auburn 98042 Lake Morton-Berrydale 98038 Hobart 98025 98030 Kent 98002 Auburn 98058 Fairwood
Other ZIP codes in King County
98001 98002 98003 98004 98005 98006 98007 98008 98011 98014 98019 98022 98023 98024 98025 98027 98028 98029 98030 98031 98032 98033 98034 98038 All King County frost dates · Washington frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
- Soil-temp heads-up
- Weekly yard to-dos
Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.