Fall in zone 5bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 97873 (Seneca, 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, John Day, OR (20 miles away).
- Average last spring frostMay 2850% chance of a 32°F freeze after this date
- Average first fall frostSep 1850% chance of a 32°F freeze by this date
- Growing season (frost-free)113 daysmedian, 32°F threshold
- USDA hardiness zone5b-15 to -10°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
58°F 55°F or warmer
24-hour average · latest 59°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of John Day 35 WNW (44 mi), Riley 10 WSW (57 mi).
4-inch depth
58°F 55°F or warmer
24-hour average · latest 59°F, as of Oct 18, 1:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of John Day 35 WNW (44 mi), Riley 10 WSW (57 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 97873 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 58°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent (annual bluegrass, winter weeds): window open as soil cools through the 70s and 60s.
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 12 |
| 50% (the "average" last frost) | May 28 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 15 |
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 2 |
| 50% (the "average" first frost) | Sep 18 |
| 90% (late: most years have frozen by now) | Oct 4 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Jun 19 | Sep 2 |
| 32°F (freeze) | May 28 | Sep 18 |
| 28°F (hard freeze) | May 8 | Oct 1 |
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 97873
Dates count from your average last spring frost (May 28) and first fall frost (Sep 18). 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 2–16 | Jun 4–18 (transplant) | – |
| Pepper (sweet and hot) | Mar 19–Apr 2 | Jun 11–25 (transplant) | – |
| Eggplant | Mar 19–Apr 2 | Jun 11–25 (transplant) | – |
| Tomatillo | Apr 2–16 | Jun 4–18 (transplant) | – |
| Lettuce | Apr 2–16 | May 7–28 (transplant) Apr 30–Jun 11 (sow outdoors) | Jul 24–Aug 14 (transplant) Jul 10–Aug 7 (sowing) |
| Spinach | – | Apr 16–May 7 (sow outdoors) | Jul 24–Aug 14 (sowing) |
| Kale | Apr 2–16 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | Jun 26–Jul 24 (transplant) Jun 12–Jul 10 (sowing) |
| Collards | Apr 2–16 | Apr 30–May 28 (transplant) Apr 30–May 28 (sow outdoors) | Jun 26–Jul 24 (transplant) Jun 12–Jul 10 (sowing) |
| Broccoli | Mar 19–Apr 2 | Apr 30–May 14 (transplant) | Jun 12–Jul 10 (transplant) |
| Cabbage | Mar 19–Apr 2 | Apr 30–May 14 (transplant) | Jun 12–Jul 10 (transplant) |
| Cauliflower | Mar 19–Apr 2 | May 14–28 (transplant) | Jun 12–Jul 10 (transplant) |
| Brussels sprouts | Mar 5–19 | Apr 30–May 14 (transplant) | May 29–Jun 19 (transplant) |
| Kohlrabi | Apr 2–16 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | Jul 10–24 (sowing) |
| Bok choy / Asian greens | – | Apr 30–May 14 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Arugula | – | Apr 30–May 28 (sow outdoors) | Jul 24–Aug 21 (sowing) |
| Mustard greens | – | Apr 30–May 21 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Swiss chard | Apr 16–30 | May 14–Jun 4 (transplant) May 14–Jun 11 (sow outdoors) | Jul 10–24 (sowing) |
| Beet | – | Apr 30–May 28 (sow outdoors) | Jul 10–24 (sowing) |
| Carrot | – | May 7–Jun 4 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Radish | – | Apr 23–Jun 4 (sow outdoors) | Aug 7–21 (sowing) |
| Turnip | – | Apr 30–May 21 (sow outdoors) | Jul 10–24 (sowing) |
| Parsnip | – | May 7–28 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 2–30 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Onion (bulbing) | Mar 5–19 | Apr 16–30 (transplant) | – |
| Green onion / scallion | – | Apr 16–May 14 (sow outdoors) | Jul 10–24 (sowing) |
| Leek | Mar 5–19 | Apr 30–May 14 (transplant) | – |
| Garlic | – | – | Aug 7–Sep 4 (sowing) |
| Shallot | – | Apr 16–30 (transplant) | Aug 7–Sep 4 (sowing) |
| Potato | – | Apr 30–May 14 (transplant) | May 29–Jun 12 (transplant) |
| Sweet potato | – | Jun 18–Jul 2 (transplant) | – |
| Sweet corn | – | Jun 4–18 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 4–18 (sow outdoors) | – |
| Bean, pole | – | Jun 4–18 (sow outdoors) | – |
| Lima bean | – | Jun 11–25 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 18–Jul 9 (sow outdoors) | – |
| Cucumber | Apr 30–May 7 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Summer squash / zucchini | Apr 30–May 7 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Winter squash | Apr 30–May 7 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Pumpkin | – | Jun 4–18 (sow outdoors) | – |
| Watermelon | Apr 30–May 7 | Jun 11–25 (transplant) Jun 11–25 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 30–May 7 | Jun 11–25 (transplant) Jun 11–25 (sow outdoors) | – |
| Okra | Apr 16–30 | Jun 11–25 (transplant) Jun 11–25 (sow outdoors) | – |
| Celery | Mar 5–19 | Jun 4–11 (transplant) | – |
| Basil | Apr 16–30 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Cilantro | – | May 14–Jun 11 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Parsley | Mar 19–Apr 2 | May 14–28 (transplant) May 7–28 (sow outdoors) | – |
| Dill | – | May 28–Jun 11 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Sunflower | – | May 28–Jun 11 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 30–May 14 (transplant) | – |
| Rhubarb (crowns) | – | Apr 30–May 14 (transplant) | – |
| Strawberry (plants) | – | Apr 30–May 14 (transplant) | Jul 10–Aug 7 (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: John Day, OR (NOAA GHCN-Daily ID USC00354291), elevation 3,063 ft, 20.4 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 | 37 mi | Jun 11 | Sep 6 |
| Drewsey, OR | 38 mi | Jun 5 | Sep 5 |
| Long Creek, OR | 41 mi | Jun 5 | Sep 14 |
The average last-frost dates of these stations span 14 days, a rough guide to local variation. See data sources & methods.
Frost questions for 97873
When is the last frost in 97873?
The average (50% chance) last spring freeze of 32°F for ZIP 97873 is May 28. For a more cautious planting date, use June 15, when only 1 year in 10 still sees a later freeze.
When is the first frost in 97873?
The average first fall freeze is September 18. In 1 year in 10 it comes by September 2.
What hardiness zone is 97873?
ZIP 97873 is in USDA zone 5b (-15 to -10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 97873 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
97820 Canyon City 97845 John Day 97865 Mount Vernon 97869 Prairie City 97904 97825 Dayville 97720 Burns 97751
Other ZIP codes in Grant County
97817 97820 97825 97845 97848 97856 97864 97865 97869 97877 All Grant County frost dates · Oregon frost dates
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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.