Fall in zone 6bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 99181 (Valley, 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, Chewelah, WA (9 miles away).
- Average last spring frostMay 1650% chance of a 32°F freeze after this date
- Average first fall frostSep 1550% chance of a 32°F freeze by this date
- Growing season (frost-free)120 daysmedian, 32°F threshold
- USDA hardiness zone6b-5 to 0°F avg. coldest night
Get The Dial for 99181 (Valley)
Frost and freeze alerts from the NWS forecast for 99181, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
- 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.
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
46°F Below 50°F
24-hour average · latest 47°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Spokane 17 SSW (51 mi).
4-inch depth
47°F Below 50°F
24-hour average · latest 49°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Spokane 17 SSW (51 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 99181 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 47°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 mid-April to mid-May).
Fertilizer window
Lawn region: Mountain West and High Plains. Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
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) | Apr 30 |
| 50% (the "average" last frost) | May 16 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 7 |
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) | Sep 1 |
| 50% (the "average" first frost) | Sep 15 |
| 90% (late: most years have frozen by now) | Sep 29 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | n/a | n/a |
| 32°F (freeze) | May 16 | Sep 15 |
| 28°F (hard freeze) | Apr 30 | Sep 28 |
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 99181
Dates count from your average last spring frost (May 16) and first fall frost (Sep 15). 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 | Mar 21–Apr 4 | May 23–Jun 6 (transplant) | – |
| Pepper (sweet and hot) | Mar 7–21 | May 30–Jun 13 (transplant) | – |
| Eggplant | Mar 7–21 | May 30–Jun 13 (transplant) | – |
| Tomatillo | Mar 21–Apr 4 | May 23–Jun 6 (transplant) | – |
| Lettuce | Mar 21–Apr 4 | Apr 25–May 16 (transplant) Apr 18–May 30 (sow outdoors) | Jul 21–Aug 11 (transplant) Jul 7–Aug 4 (sowing) |
| Spinach | – | Apr 4–25 (sow outdoors) | Jul 21–Aug 11 (sowing) |
| Kale | Mar 21–Apr 4 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | Jun 23–Jul 21 (transplant) Jun 9–Jul 7 (sowing) |
| Collards | Mar 21–Apr 4 | Apr 18–May 16 (transplant) Apr 18–May 16 (sow outdoors) | Jun 23–Jul 21 (transplant) Jun 9–Jul 7 (sowing) |
| Broccoli | Mar 7–21 | Apr 18–May 2 (transplant) | Jun 9–Jul 7 (transplant) |
| Cabbage | Mar 7–21 | Apr 18–May 2 (transplant) | Jun 9–Jul 7 (transplant) |
| Cauliflower | Mar 7–21 | May 2–16 (transplant) | Jun 9–Jul 7 (transplant) |
| Brussels sprouts | Feb 21–Mar 7 | Apr 18–May 2 (transplant) | May 26–Jun 16 (transplant) |
| Kohlrabi | Mar 21–Apr 4 | Apr 18–May 2 (transplant) Apr 18–May 2 (sow outdoors) | Jul 7–21 (sowing) |
| Bok choy / Asian greens | – | Apr 18–May 2 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Arugula | – | Apr 18–May 16 (sow outdoors) | Jul 21–Aug 18 (sowing) |
| Mustard greens | – | Apr 18–May 9 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Swiss chard | Apr 4–18 | May 2–23 (transplant) May 2–30 (sow outdoors) | Jul 7–21 (sowing) |
| Beet | – | Apr 18–May 16 (sow outdoors) | Jul 7–21 (sowing) |
| Carrot | – | Apr 25–May 23 (sow outdoors) | Jun 23–Jul 7 (sowing) |
| Radish | – | Apr 11–May 23 (sow outdoors) | Aug 4–18 (sowing) |
| Turnip | – | Apr 18–May 9 (sow outdoors) | Jul 7–21 (sowing) |
| Parsnip | – | Apr 25–May 16 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 21–Apr 18 (sow outdoors) | Jun 23–Jul 7 (sowing) |
| Onion (bulbing) | Feb 21–Mar 7 | Apr 4–18 (transplant) | – |
| Green onion / scallion | – | Apr 4–May 2 (sow outdoors) | Jul 7–21 (sowing) |
| Leek | Feb 21–Mar 7 | Apr 18–May 2 (transplant) | – |
| Garlic | – | – | Aug 4–Sep 1 (sowing) |
| Shallot | – | Apr 4–18 (transplant) | Aug 4–Sep 1 (sowing) |
| Potato | – | Apr 18–May 2 (transplant) | May 26–Jun 9 (transplant) |
| Sweet potato | – | Jun 6–20 (transplant) | – |
| Sweet corn | – | May 23–Jun 6 (sow outdoors) | – |
| Bean, bush (snap) | – | May 23–Jun 6 (sow outdoors) | – |
| Bean, pole | – | May 23–Jun 6 (sow outdoors) | – |
| Lima bean | – | May 30–Jun 13 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 6–27 (sow outdoors) | – |
| Cucumber | Apr 18–25 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Summer squash / zucchini | Apr 18–25 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Winter squash | Apr 18–25 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Pumpkin | – | May 23–Jun 6 (sow outdoors) | – |
| Watermelon | Apr 18–25 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 18–25 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Okra | Apr 4–18 | May 30–Jun 13 (transplant) May 30–Jun 13 (sow outdoors) | – |
| Celery | Feb 21–Mar 7 | May 23–30 (transplant) | – |
| Basil | Apr 4–18 | May 23–Jun 6 (transplant) May 23–Jun 6 (sow outdoors) | – |
| Cilantro | – | May 2–30 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Parsley | Mar 7–21 | May 2–16 (transplant) Apr 25–May 16 (sow outdoors) | – |
| Dill | – | May 16–30 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Sunflower | – | May 16–30 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 18–May 2 (transplant) | – |
| Rhubarb (crowns) | – | Apr 18–May 2 (transplant) | – |
| Strawberry (plants) | – | Apr 18–May 2 (transplant) | Jul 7–Aug 4 (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: Chewelah, WA (NOAA GHCN-Daily ID USC00451395), elevation 1,670 ft, 8.9 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Deer Park AP, WA | 20 mi | May 22 | Sep 14 |
| Colville, WA | 30 mi | May 2 | Oct 2 |
| Spokane WFO, WA | 33 mi | May 10 | Sep 26 |
The average last-frost dates of these stations span 20 days, a rough guide to local variation. See data sources & methods.
Frost questions for 99181
When is the last frost in 99181?
The average (50% chance) last spring freeze of 32°F for ZIP 99181 is May 16. For a more cautious planting date, use June 7, when only 1 year in 10 still sees a later freeze.
When is the first frost in 99181?
The average first fall freeze is September 15. In 1 year in 10 it comes by September 1.
What hardiness zone is 99181?
ZIP 99181 is in USDA zone 6b (-5 to 0°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 99181 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
99173 Springdale 99148 Loon Lake 99109 Chewelah 99110 Clayton 99101 Addy 99137 99034 99006 Deer Park
Other ZIP codes in Stevens County
99013 99034 99040 99101 99109 99110 99114 99126 99129 99131 99137 99148 99151 99157 99167 99173 All Stevens County frost dates · Washington frost dates
Never miss a frost: get The Dial
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.