Frost dates for ZIP 98639 (North Bonneville, 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, Bonneville Dam, OR (1 miles away).
- Average last spring frostMar 1450% chance of a 32°F freeze after this date
- Average first fall frostNov 2750% chance of a 32°F freeze by this date
- Growing season (frost-free)257 daysmedian, 32°F threshold
- USDA hardiness zone9a20 to 25°F avg. coldest night
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This week in your yard
As of Oct 17, 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 98639 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
- Lettuce: fall transplant Oct 2–23
- Spinach: fall sowing Oct 2–23
- Arugula: fall sowing Oct 2–30
- Radish: fall sowing Oct 16–30
- Garlic: fall sowing Oct 16–Nov 13
- Shallot: fall sowing Oct 16–Nov 13
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 27: 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) | Feb 19 |
| 50% (the "average" last frost) | Mar 14 |
| 10% (cautious: only 1 year in 10 freezes later) | Apr 4 |
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) | Nov 8 |
| 50% (the "average" first frost) | Nov 27 |
| 90% (late: most years have frozen by now) | Dec 15 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 15 | Nov 10 |
| 32°F (freeze) | Mar 14 | Nov 27 |
| 28°F (hard freeze) | Feb 14 | Dec 14 |
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 98639
Dates count from your average last spring frost (Mar 14) and first fall frost (Nov 27). 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 | Jan 17–31 | Mar 21–Apr 4 (transplant) | Jul 31–Aug 28 (transplant) |
| Pepper (sweet and hot) | Jan 3–17 | Mar 28–Apr 11 (transplant) | Aug 7–28 (transplant) |
| Eggplant | Jan 3–17 | Mar 28–Apr 11 (transplant) | Aug 7–28 (transplant) |
| Tomatillo | Jan 17–31 | Mar 21–Apr 4 (transplant) | – |
| Lettuce | Jan 17–31 | Feb 21–Mar 14 (transplant) Feb 14–Mar 28 (sow outdoors) | Oct 2–23 (transplant) Sep 18–Oct 16 (sowing) |
| Spinach | – | Jan 31–Feb 21 (sow outdoors) | Oct 2–23 (sowing) |
| Kale | Jan 17–31 | Feb 14–28 (transplant) Feb 14–28 (sow outdoors) | Sep 4–Oct 2 (transplant) Aug 21–Sep 18 (sowing) |
| Collards | Jan 17–31 | Feb 14–Mar 14 (transplant) Feb 14–Mar 14 (sow outdoors) | Sep 4–Oct 2 (transplant) Aug 21–Sep 18 (sowing) |
| Broccoli | Jan 3–17 | Feb 14–28 (transplant) | Aug 21–Sep 18 (transplant) |
| Cabbage | Jan 3–17 | Feb 14–28 (transplant) | Aug 21–Sep 18 (transplant) |
| Cauliflower | Jan 3–17 | Feb 28–Mar 14 (transplant) | Aug 21–Sep 18 (transplant) |
| Brussels sprouts | Dec 20–Jan 3 | Feb 14–28 (transplant) | Aug 7–28 (transplant) |
| Kohlrabi | Jan 17–31 | Feb 14–28 (transplant) Feb 14–28 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Bok choy / Asian greens | – | Feb 14–28 (sow outdoors) | Oct 2–16 (sowing) |
| Arugula | – | Feb 14–Mar 14 (sow outdoors) | Oct 2–30 (sowing) |
| Mustard greens | – | Feb 14–Mar 7 (sow outdoors) | Oct 2–16 (sowing) |
| Swiss chard | Jan 31–Feb 14 | Feb 28–Mar 21 (transplant) Feb 28–Mar 28 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Beet | – | Feb 14–Mar 14 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Carrot | – | Feb 21–Mar 21 (sow outdoors) | Sep 4–18 (sowing) |
| Radish | – | Feb 7–Mar 21 (sow outdoors) | Oct 16–30 (sowing) |
| Turnip | – | Feb 14–Mar 7 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Parsnip | – | Feb 21–Mar 14 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Jan 17–Feb 14 (sow outdoors) | Sep 4–18 (sowing) |
| Onion (bulbing) | Dec 20–Jan 3 | Jan 31–Feb 14 (transplant) | – |
| Green onion / scallion | – | Jan 31–Feb 28 (sow outdoors) | Sep 18–Oct 2 (sowing) |
| Leek | Dec 20–Jan 3 | Feb 14–28 (transplant) | – |
| Garlic | – | – | Oct 16–Nov 13 (sowing) |
| Shallot | – | Jan 31–Feb 14 (transplant) | Oct 16–Nov 13 (sowing) |
| Potato | – | Feb 14–28 (transplant) | Aug 7–21 (transplant) |
| Sweet potato | – | Apr 4–18 (transplant) | – |
| Sweet corn | – | Mar 21–Apr 4 (sow outdoors) | – |
| Bean, bush (snap) | – | Mar 21–Apr 4 (sow outdoors) | Sep 4–18 (sowing) |
| Bean, pole | – | Mar 21–Apr 4 (sow outdoors) | – |
| Lima bean | – | Mar 28–Apr 11 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Apr 4–25 (sow outdoors) | – |
| Cucumber | Feb 14–21 | Mar 21–Apr 4 (transplant) Mar 21–Apr 4 (sow outdoors) | Sep 4–18 (sowing) |
| Summer squash / zucchini | Feb 14–21 | Mar 21–Apr 4 (transplant) Mar 21–Apr 4 (sow outdoors) | Sep 4–18 (sowing) |
| Winter squash | Feb 14–21 | Mar 21–Apr 4 (transplant) Mar 21–Apr 4 (sow outdoors) | – |
| Pumpkin | – | Mar 21–Apr 4 (sow outdoors) | – |
| Watermelon | Feb 14–21 | Mar 28–Apr 11 (transplant) Mar 28–Apr 11 (sow outdoors) | – |
| Cantaloupe / muskmelon | Feb 14–21 | Mar 28–Apr 11 (transplant) Mar 28–Apr 11 (sow outdoors) | – |
| Okra | Jan 31–Feb 14 | Mar 28–Apr 11 (transplant) Mar 28–Apr 11 (sow outdoors) | – |
| Celery | Dec 20–Jan 3 | Mar 21–28 (transplant) | – |
| Basil | Jan 31–Feb 14 | Mar 21–Apr 4 (transplant) Mar 21–Apr 4 (sow outdoors) | – |
| Cilantro | – | Feb 28–Mar 28 (sow outdoors) | Oct 2–16 (sowing) |
| Parsley | Jan 3–17 | Feb 28–Mar 14 (transplant) Feb 21–Mar 14 (sow outdoors) | – |
| Dill | – | Mar 14–28 (sow outdoors) | Oct 2–16 (sowing) |
| Sunflower | – | Mar 14–28 (sow outdoors) | – |
| Asparagus (crowns) | – | Feb 14–28 (transplant) | – |
| Rhubarb (crowns) | – | Feb 14–28 (transplant) | – |
| Strawberry (plants) | – | Feb 14–28 (transplant) | Sep 18–Oct 16 (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: Bonneville Dam, OR (NOAA GHCN-Daily ID USC00350897), elevation 62 ft, 0.7 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Cascade Locks, OR | 5 mi | Mar 24 | Nov 20 |
| Skamania Fish Hatchery, WA | 12 mi | Apr 29 | Oct 22 |
| Carson Fish Hatchery, WA | 16 mi | May 2 | Oct 9 |
The average last-frost dates of these stations span 50 days, a rough guide to local variation. See data sources & methods.
Frost questions for 98639
When is the last frost in 98639?
The average (50% chance) last spring freeze of 32°F for ZIP 98639 is March 14. For a more cautious planting date, use April 4, when only 1 year in 10 still sees a later freeze.
When is the first frost in 98639?
The average first fall freeze is November 27. In 1 year in 10 it comes by November 8.
What hardiness zone is 98639?
ZIP 98639 is in USDA zone 9a (20 to 25°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 98639 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
98648 Stevenson 97014 Cascade Locks 98610 Carson 98671 Washougal 97019 98605 Bingen 97031 Hood River 97011 Mount Hood Villages
Other ZIP codes in Skamania County
98605 98610 98616 98648 98651 98671 All Skamania County frost dates · Washington frost dates
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