Fall in zone 6aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 98859 (Okanogan County, 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, Republic, WA (14 miles away).
- Average last spring frostMay 3050% chance of a 32°F freeze after this date
- Average first fall frostSep 1050% chance of a 32°F freeze by this date
- Growing season (frost-free)102 daysmedian, 32°F threshold
- USDA hardiness zone6a-10 to -5°F avg. coldest night
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Frost and freeze alerts from the NWS forecast for 98859, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
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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 98859 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 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) | May 11 |
| 50% (the "average" last frost) | May 30 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 17 |
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) | Aug 28 |
| 50% (the "average" first frost) | Sep 10 |
| 90% (late: most years have frozen by now) | Sep 25 |
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 30 | Sep 10 |
| 28°F (hard freeze) | May 12 | Sep 24 |
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 98859
Dates count from your average last spring frost (May 30) and first fall frost (Sep 10). 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 | Apr 4–18 | Jun 6–20 (transplant) | – |
| Pepper (sweet and hot) | Mar 21–Apr 4 | Jun 13–27 (transplant) | – |
| Eggplant | Mar 21–Apr 4 | Jun 13–27 (transplant) | – |
| Tomatillo | Apr 4–18 | Jun 6–20 (transplant) | – |
| Lettuce | Apr 4–18 | May 9–30 (transplant) May 2–Jun 13 (sow outdoors) | Jul 16–Aug 6 (transplant) Jul 2–30 (sowing) |
| Spinach | – | Apr 18–May 9 (sow outdoors) | Jul 16–Aug 6 (sowing) |
| Kale | Apr 4–18 | May 2–16 (transplant) May 2–16 (sow outdoors) | Jun 18–Jul 16 (transplant) Jun 4–Jul 2 (sowing) |
| Collards | Apr 4–18 | May 2–30 (transplant) May 2–30 (sow outdoors) | Jun 18–Jul 16 (transplant) Jun 4–Jul 2 (sowing) |
| Broccoli | Mar 21–Apr 4 | May 2–16 (transplant) | Jun 4–Jul 2 (transplant) |
| Cabbage | Mar 21–Apr 4 | May 2–16 (transplant) | Jun 4–Jul 2 (transplant) |
| Cauliflower | Mar 21–Apr 4 | May 16–30 (transplant) | Jun 4–Jul 2 (transplant) |
| Brussels sprouts | Mar 7–21 | May 2–16 (transplant) | May 21–Jun 11 (transplant) |
| Kohlrabi | Apr 4–18 | May 2–16 (transplant) May 2–16 (sow outdoors) | Jul 2–16 (sowing) |
| Bok choy / Asian greens | – | May 2–16 (sow outdoors) | Jul 16–30 (sowing) |
| Arugula | – | May 2–30 (sow outdoors) | Jul 16–Aug 13 (sowing) |
| Mustard greens | – | May 2–23 (sow outdoors) | Jul 16–30 (sowing) |
| Swiss chard | Apr 18–May 2 | May 16–Jun 6 (transplant) May 16–Jun 13 (sow outdoors) | Jul 2–16 (sowing) |
| Beet | – | May 2–30 (sow outdoors) | Jul 2–16 (sowing) |
| Carrot | – | May 9–Jun 6 (sow outdoors) | Jun 18–Jul 2 (sowing) |
| Radish | – | Apr 25–Jun 6 (sow outdoors) | Jul 30–Aug 13 (sowing) |
| Turnip | – | May 2–23 (sow outdoors) | Jul 2–16 (sowing) |
| Parsnip | – | May 9–30 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 4–May 2 (sow outdoors) | Jun 18–Jul 2 (sowing) |
| Onion (bulbing) | Mar 7–21 | Apr 18–May 2 (transplant) | – |
| Green onion / scallion | – | Apr 18–May 16 (sow outdoors) | Jul 2–16 (sowing) |
| Leek | Mar 7–21 | May 2–16 (transplant) | – |
| Garlic | – | – | Jul 30–Aug 27 (sowing) |
| Shallot | – | Apr 18–May 2 (transplant) | Jul 30–Aug 27 (sowing) |
| Potato | – | May 2–16 (transplant) | May 21–Jun 4 (transplant) |
| Sweet potato | – | Jun 20–Jul 4 (transplant) | – |
| Sweet corn | – | Jun 6–20 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 6–20 (sow outdoors) | – |
| Bean, pole | – | Jun 6–20 (sow outdoors) | – |
| Lima bean | – | Jun 13–27 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 20–Jul 11 (sow outdoors) | – |
| Cucumber | May 2–9 | Jun 6–20 (transplant) Jun 6–20 (sow outdoors) | – |
| Summer squash / zucchini | May 2–9 | Jun 6–20 (transplant) Jun 6–20 (sow outdoors) | – |
| Winter squash | May 2–9 | Jun 6–20 (transplant) Jun 6–20 (sow outdoors) | – |
| Pumpkin | – | Jun 6–20 (sow outdoors) | – |
| Watermelon | May 2–9 | Jun 13–27 (transplant) Jun 13–27 (sow outdoors) | – |
| Cantaloupe / muskmelon | May 2–9 | Jun 13–27 (transplant) Jun 13–27 (sow outdoors) | – |
| Okra | Apr 18–May 2 | Jun 13–27 (transplant) Jun 13–27 (sow outdoors) | – |
| Celery | Mar 7–21 | Jun 6–13 (transplant) | – |
| Basil | Apr 18–May 2 | Jun 6–20 (transplant) Jun 6–20 (sow outdoors) | – |
| Cilantro | – | May 16–Jun 13 (sow outdoors) | Jul 16–30 (sowing) |
| Parsley | Mar 21–Apr 4 | May 16–30 (transplant) May 9–30 (sow outdoors) | – |
| Dill | – | May 30–Jun 13 (sow outdoors) | Jul 16–30 (sowing) |
| Sunflower | – | May 30–Jun 13 (sow outdoors) | – |
| Asparagus (crowns) | – | May 2–16 (transplant) | – |
| Rhubarb (crowns) | – | May 2–16 (transplant) | – |
| Strawberry (plants) | – | May 2–16 (transplant) | Jul 2–30 (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: Republic, WA (NOAA GHCN-Daily ID USC00456974), elevation 2,555 ft, 14.5 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Tonasket 11NE, WA | 14 mi | May 6 | Oct 6 |
| Tonasket 4 NNE, WA | 21 mi | Apr 26 | Oct 10 |
| Omak AP, WA | 35 mi | Apr 30 | Oct 7 |
The average last-frost dates of these stations span 35 days, a rough guide to local variation. See data sources & methods.
Frost questions for 98859
When is the last frost in 98859?
The average (50% chance) last spring freeze of 32°F for ZIP 98859 is May 30. For a more cautious planting date, use June 17, when only 1 year in 10 still sees a later freeze.
When is the first frost in 98859?
The average first fall freeze is September 10. In 1 year in 10 it comes by August 28.
What hardiness zone is 98859?
ZIP 98859 is in USDA zone 6a (-10 to -5°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 98859 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
98844 Oroville 99150 Malo 99118 Curlew 98855 Tonasket 99166 Curlew Lake 99121 Danville 98849 Riverside 99160 Orient
Other ZIP codes in Okanogan County
98812 98814 98819 98827 98829 98833 98834 98840 98841 98844 98846 98849 98855 98856 98862 99116 99124 99155 All Okanogan 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.