Fall in zone 8bPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 98238 (Conway, 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, Mt Vernon 3 WNW, WA (8 miles away).
- Average last spring frostMar 2450% chance of a 32°F freeze after this date
- Average first fall frostNov 350% chance of a 32°F freeze by this date
- Growing season (frost-free)224 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
50°F 50–55°F
24-hour average · latest 50°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Darrington 21 NNE (43 mi).
4-inch depth
50°F 50–55°F
24-hour average · latest 50°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Darrington 21 NNE (43 mi).
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 98238 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 50°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent window is mostly past. Next: spring, when soil reaches 50°F (typically 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
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 3: 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 3 |
| 50% (the "average" last frost) | Mar 24 |
| 10% (cautious: only 1 year in 10 freezes later) | Apr 14 |
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 12 |
| 50% (the "average" first frost) | Nov 3 |
| 90% (late: most years have frozen by now) | Nov 25 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 18 | Oct 16 |
| 32°F (freeze) | Mar 24 | Nov 3 |
| 28°F (hard freeze) | Feb 27 | Nov 25 |
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 98238
Dates count from your average last spring frost (Mar 24) and first fall frost (Nov 3). 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 27–Feb 10 | Mar 31–Apr 14 (transplant) | Jul 7–Aug 4 (transplant) |
| Pepper (sweet and hot) | Jan 13–27 | Apr 7–21 (transplant) | Jul 14–Aug 4 (transplant) |
| Eggplant | Jan 13–27 | Apr 7–21 (transplant) | Jul 14–Aug 4 (transplant) |
| Tomatillo | Jan 27–Feb 10 | Mar 31–Apr 14 (transplant) | – |
| Lettuce | Jan 27–Feb 10 | Mar 3–24 (transplant) Feb 24–Apr 7 (sow outdoors) | Sep 8–29 (transplant) Aug 25–Sep 22 (sowing) |
| Spinach | – | Feb 10–Mar 3 (sow outdoors) | Sep 8–29 (sowing) |
| Kale | Jan 27–Feb 10 | Feb 24–Mar 10 (transplant) Feb 24–Mar 10 (sow outdoors) | Aug 11–Sep 8 (transplant) Jul 28–Aug 25 (sowing) |
| Collards | Jan 27–Feb 10 | Feb 24–Mar 24 (transplant) Feb 24–Mar 24 (sow outdoors) | Aug 11–Sep 8 (transplant) Jul 28–Aug 25 (sowing) |
| Broccoli | Jan 13–27 | Feb 24–Mar 10 (transplant) | Jul 28–Aug 25 (transplant) |
| Cabbage | Jan 13–27 | Feb 24–Mar 10 (transplant) | Jul 28–Aug 25 (transplant) |
| Cauliflower | Jan 13–27 | Mar 10–24 (transplant) | Jul 28–Aug 25 (transplant) |
| Brussels sprouts | Dec 30–Jan 13 | Feb 24–Mar 10 (transplant) | Jul 14–Aug 4 (transplant) |
| Kohlrabi | Jan 27–Feb 10 | Feb 24–Mar 10 (transplant) Feb 24–Mar 10 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Bok choy / Asian greens | – | Feb 24–Mar 10 (sow outdoors) | Sep 8–22 (sowing) |
| Arugula | – | Feb 24–Mar 24 (sow outdoors) | Sep 8–Oct 6 (sowing) |
| Mustard greens | – | Feb 24–Mar 17 (sow outdoors) | Sep 8–22 (sowing) |
| Swiss chard | Feb 10–24 | Mar 10–31 (transplant) Mar 10–Apr 7 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Beet | – | Feb 24–Mar 24 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Carrot | – | Mar 3–31 (sow outdoors) | Aug 11–25 (sowing) |
| Radish | – | Feb 17–Mar 31 (sow outdoors) | Sep 22–Oct 6 (sowing) |
| Turnip | – | Feb 24–Mar 17 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Parsnip | – | Mar 3–24 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Jan 27–Feb 24 (sow outdoors) | Aug 11–25 (sowing) |
| Onion (bulbing) | Dec 30–Jan 13 | Feb 10–24 (transplant) | – |
| Green onion / scallion | – | Feb 10–Mar 10 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Leek | Dec 30–Jan 13 | Feb 24–Mar 10 (transplant) | – |
| Garlic | – | – | Sep 22–Oct 20 (sowing) |
| Shallot | – | Feb 10–24 (transplant) | Sep 22–Oct 20 (sowing) |
| Potato | – | Feb 24–Mar 10 (transplant) | Jul 14–28 (transplant) |
| Sweet potato | – | Apr 14–28 (transplant) | – |
| Sweet corn | – | Mar 31–Apr 14 (sow outdoors) | – |
| Bean, bush (snap) | – | Mar 31–Apr 14 (sow outdoors) | Aug 11–25 (sowing) |
| Bean, pole | – | Mar 31–Apr 14 (sow outdoors) | – |
| Lima bean | – | Apr 7–21 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Apr 14–May 5 (sow outdoors) | – |
| Cucumber | Feb 24–Mar 3 | Mar 31–Apr 14 (transplant) Mar 31–Apr 14 (sow outdoors) | Aug 11–25 (sowing) |
| Summer squash / zucchini | Feb 24–Mar 3 | Mar 31–Apr 14 (transplant) Mar 31–Apr 14 (sow outdoors) | Aug 11–25 (sowing) |
| Winter squash | Feb 24–Mar 3 | Mar 31–Apr 14 (transplant) Mar 31–Apr 14 (sow outdoors) | – |
| Pumpkin | – | Mar 31–Apr 14 (sow outdoors) | – |
| Watermelon | Feb 24–Mar 3 | Apr 7–21 (transplant) Apr 7–21 (sow outdoors) | – |
| Cantaloupe / muskmelon | Feb 24–Mar 3 | Apr 7–21 (transplant) Apr 7–21 (sow outdoors) | – |
| Okra | Feb 10–24 | Apr 7–21 (transplant) Apr 7–21 (sow outdoors) | – |
| Celery | Dec 30–Jan 13 | Mar 31–Apr 7 (transplant) | – |
| Basil | Feb 10–24 | Mar 31–Apr 14 (transplant) Mar 31–Apr 14 (sow outdoors) | – |
| Cilantro | – | Mar 10–Apr 7 (sow outdoors) | Sep 8–22 (sowing) |
| Parsley | Jan 13–27 | Mar 10–24 (transplant) Mar 3–24 (sow outdoors) | – |
| Dill | – | Mar 24–Apr 7 (sow outdoors) | Sep 8–22 (sowing) |
| Sunflower | – | Mar 24–Apr 7 (sow outdoors) | – |
| Asparagus (crowns) | – | Feb 24–Mar 10 (transplant) | – |
| Rhubarb (crowns) | – | Feb 24–Mar 10 (transplant) | – |
| Strawberry (plants) | – | Feb 24–Mar 10 (transplant) | Aug 25–Sep 22 (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: Mt Vernon 3 WNW, WA (NOAA GHCN-Daily ID USC00455678), elevation 14 ft, 7.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Sedro-woolley, WA | 12 mi | Mar 27 | Nov 6 |
| Arlington, WA | 14 mi | Apr 22 | Oct 19 |
| Whidbey Island NAS, WA | 15 mi | Mar 13 | Nov 14 |
The average last-frost dates of these stations span 40 days, a rough guide to local variation. See data sources & methods.
Frost questions for 98238
When is the last frost in 98238?
The average (50% chance) last spring freeze of 32°F for ZIP 98238 is March 24. For a more cautious planting date, use April 14, when only 1 year in 10 still sees a later freeze.
When is the first frost in 98238?
The average first fall freeze is November 3. In 1 year in 10 it comes by October 12.
What hardiness zone is 98238?
ZIP 98238 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 98238 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
98273 Mount Vernon 98292 Kayak Point 98257 La Conner 98274 Big Lake 98235 Clear Lake 98282 Camano 98233 Burlington 98277 Oak Harbor
Other ZIP codes in Skagit County
98221 98232 98233 98235 98237 98255 98257 98263 98267 98273 98274 98284 All Skagit 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
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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.