Fall in zone 6aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 97904 (Harney County, OR)
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, Drewsey, OR (8 miles away).
- Average last spring frostJun 550% chance of a 32°F freeze after this date
- Average first fall frostSep 550% chance of a 32°F freeze by this date
- Growing season (frost-free)91 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 97904, 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 97904 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 17 |
| 50% (the "average" last frost) | Jun 5 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 26 |
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 20 |
| 50% (the "average" first frost) | Sep 5 |
| 90% (late: most years have frozen by now) | Sep 21 |
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) | Jun 5 | Sep 5 |
| 28°F (hard freeze) | May 18 | Sep 17 |
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 97904
Dates count from your average last spring frost (Jun 5) and first fall frost (Sep 5). 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 10–24 | Jun 12–26 (transplant) | – |
| Pepper (sweet and hot) | Mar 27–Apr 10 | Jun 19–Jul 3 (transplant) | – |
| Eggplant | Mar 27–Apr 10 | Jun 19–Jul 3 (transplant) | – |
| Tomatillo | Apr 10–24 | Jun 12–26 (transplant) | – |
| Lettuce | Apr 10–24 | May 15–Jun 5 (transplant) May 8–Jun 19 (sow outdoors) | Jul 11–Aug 1 (transplant) Jun 27–Jul 25 (sowing) |
| Spinach | – | Apr 24–May 15 (sow outdoors) | Jul 11–Aug 1 (sowing) |
| Kale | Apr 10–24 | May 8–22 (transplant) May 8–22 (sow outdoors) | Jun 13–Jul 11 (transplant) May 30–Jun 27 (sowing) |
| Collards | Apr 10–24 | May 8–Jun 5 (transplant) May 8–Jun 5 (sow outdoors) | Jun 13–Jul 11 (transplant) |
| Broccoli | Mar 27–Apr 10 | May 8–22 (transplant) | May 30–Jun 27 (transplant) |
| Cabbage | Mar 27–Apr 10 | May 8–22 (transplant) | May 30–Jun 27 (transplant) |
| Cauliflower | Mar 27–Apr 10 | May 22–Jun 5 (transplant) | – |
| Brussels sprouts | Mar 13–27 | May 8–22 (transplant) | – |
| Kohlrabi | Apr 10–24 | May 8–22 (transplant) May 8–22 (sow outdoors) | Jun 27–Jul 11 (sowing) |
| Bok choy / Asian greens | – | May 8–22 (sow outdoors) | Jul 11–25 (sowing) |
| Arugula | – | May 8–Jun 5 (sow outdoors) | Jul 11–Aug 8 (sowing) |
| Mustard greens | – | May 8–29 (sow outdoors) | Jul 11–25 (sowing) |
| Swiss chard | Apr 24–May 8 | May 22–Jun 12 (transplant) May 22–Jun 19 (sow outdoors) | Jun 27–Jul 11 (sowing) |
| Beet | – | May 8–Jun 5 (sow outdoors) | Jun 27–Jul 11 (sowing) |
| Carrot | – | May 15–Jun 12 (sow outdoors) | Jun 13–27 (sowing) |
| Radish | – | May 1–Jun 12 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Turnip | – | May 8–29 (sow outdoors) | Jun 27–Jul 11 (sowing) |
| Parsnip | – | May 15–Jun 5 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 10–May 8 (sow outdoors) | Jun 13–27 (sowing) |
| Onion (bulbing) | Mar 13–27 | Apr 24–May 8 (transplant) | – |
| Green onion / scallion | – | Apr 24–May 22 (sow outdoors) | Jun 27–Jul 11 (sowing) |
| Leek | Mar 13–27 | May 8–22 (transplant) | – |
| Garlic | – | – | Jul 25–Aug 22 (sowing) |
| Shallot | – | Apr 24–May 8 (transplant) | Jul 25–Aug 22 (sowing) |
| Potato | – | May 8–22 (transplant) | – |
| Sweet potato | – | Jun 26–Jul 10 (transplant) | – |
| Sweet corn | – | Jun 12–26 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 12–26 (sow outdoors) | – |
| Bean, pole | – | Jun 12–26 (sow outdoors) | – |
| Lima bean | – | Jun 19–Jul 3 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 26–Jul 17 (sow outdoors) | – |
| Cucumber | May 8–15 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Summer squash / zucchini | May 8–15 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Winter squash | May 8–15 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Pumpkin | – | Jun 12–26 (sow outdoors) | – |
| Watermelon | May 8–15 | Jun 19–Jul 3 (transplant) Jun 19–Jul 3 (sow outdoors) | – |
| Cantaloupe / muskmelon | May 8–15 | Jun 19–Jul 3 (transplant) Jun 19–Jul 3 (sow outdoors) | – |
| Okra | Apr 24–May 8 | Jun 19–Jul 3 (transplant) Jun 19–Jul 3 (sow outdoors) | – |
| Celery | Mar 13–27 | Jun 12–19 (transplant) | – |
| Basil | Apr 24–May 8 | Jun 12–26 (transplant) Jun 12–26 (sow outdoors) | – |
| Cilantro | – | May 22–Jun 19 (sow outdoors) | Jul 11–25 (sowing) |
| Parsley | Mar 27–Apr 10 | May 22–Jun 5 (transplant) May 15–Jun 5 (sow outdoors) | – |
| Dill | – | Jun 5–19 (sow outdoors) | Jul 11–25 (sowing) |
| Sunflower | – | Jun 5–19 (sow outdoors) | – |
| Asparagus (crowns) | – | May 8–22 (transplant) | – |
| Rhubarb (crowns) | – | May 8–22 (transplant) | – |
| Strawberry (plants) | – | May 8–22 (transplant) | Jun 27–Jul 25 (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: Drewsey, OR (NOAA GHCN-Daily ID USC00352415), elevation 3,515 ft, 8.3 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Burns Muni AP, OR | 31 mi | Jun 11 | Sep 6 |
| Riverside 7 SSW, OR | 33 mi | Jun 7 | Sep 6 |
| Westfall, OR | 39 mi | May 7 | Oct 3 |
The average last-frost dates of these stations span 35 days, a rough guide to local variation. See data sources & methods.
Frost questions for 97904
When is the last frost in 97904?
The average (50% chance) last spring freeze of 32°F for ZIP 97904 is June 5. For a more cautious planting date, use June 26, when only 1 year in 10 still sees a later freeze.
When is the first frost in 97904?
The average first fall freeze is September 5. In 1 year in 10 it comes by August 20.
What hardiness zone is 97904?
ZIP 97904 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 97904 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
97911 Juntura 97720 Burns 97732 Crane 97873 Seneca 97917 97869 Prairie City 97908 97920
Other ZIP codes in Harney County
97710 97720 97721 97722 97732 97736 97738 97758 All Harney County frost dates · Oregon frost dates
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- 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.