Fall in zone 7aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 83623 (Glenns Ferry, ID)
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, Glenns Ferry, ID (8 miles away).
- Average last spring frostMay 150% chance of a 32°F freeze after this date
- Average first fall frostOct 350% chance of a 32°F freeze by this date
- Growing season (frost-free)154 daysmedian, 32°F threshold
- USDA hardiness zone7a0 to 5°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
60°F 55°F or warmer
24-hour average · latest 57°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Orchard Range Site (36 mi).
4-inch depth
60°F 55°F or warmer
24-hour average · latest 60°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Orchard Range Site (36 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 83623 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 60°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) | Apr 14 |
| 50% (the "average" last frost) | May 1 |
| 10% (cautious: only 1 year in 10 freezes later) | May 16 |
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 16 |
| 50% (the "average" first frost) | Oct 3 |
| 90% (late: most years have frozen by now) | Oct 19 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 15 | Sep 21 |
| 32°F (freeze) | May 1 | Oct 3 |
| 28°F (hard freeze) | Apr 15 | Oct 16 |
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 83623
Dates count from your average last spring frost (May 1) and first fall frost (Oct 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 | Mar 6–20 | May 8–22 (transplant) | – |
| Pepper (sweet and hot) | Feb 20–Mar 6 | May 15–29 (transplant) | – |
| Eggplant | Feb 20–Mar 6 | May 15–29 (transplant) | – |
| Tomatillo | Mar 6–20 | May 8–22 (transplant) | – |
| Lettuce | Mar 6–20 | Apr 10–May 1 (transplant) Apr 3–May 15 (sow outdoors) | Aug 8–29 (transplant) Jul 25–Aug 22 (sowing) |
| Spinach | – | Mar 20–Apr 10 (sow outdoors) | Aug 8–29 (sowing) |
| Kale | Mar 6–20 | Apr 3–17 (transplant) Apr 3–17 (sow outdoors) | Jul 11–Aug 8 (transplant) Jun 27–Jul 25 (sowing) |
| Collards | Mar 6–20 | Apr 3–May 1 (transplant) Apr 3–May 1 (sow outdoors) | Jul 11–Aug 8 (transplant) Jun 27–Jul 25 (sowing) |
| Broccoli | Feb 20–Mar 6 | Apr 3–17 (transplant) | Jun 27–Jul 25 (transplant) |
| Cabbage | Feb 20–Mar 6 | Apr 3–17 (transplant) | Jun 27–Jul 25 (transplant) |
| Cauliflower | Feb 20–Mar 6 | Apr 17–May 1 (transplant) | Jun 27–Jul 25 (transplant) |
| Brussels sprouts | Feb 6–20 | Apr 3–17 (transplant) | Jun 13–Jul 4 (transplant) |
| Kohlrabi | Mar 6–20 | Apr 3–17 (transplant) Apr 3–17 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Bok choy / Asian greens | – | Apr 3–17 (sow outdoors) | Aug 8–22 (sowing) |
| Arugula | – | Apr 3–May 1 (sow outdoors) | Aug 8–Sep 5 (sowing) |
| Mustard greens | – | Apr 3–24 (sow outdoors) | Aug 8–22 (sowing) |
| Swiss chard | Mar 20–Apr 3 | Apr 17–May 8 (transplant) Apr 17–May 15 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Beet | – | Apr 3–May 1 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Carrot | – | Apr 10–May 8 (sow outdoors) | Jul 11–25 (sowing) |
| Radish | – | Mar 27–May 8 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Turnip | – | Apr 3–24 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Parsnip | – | Apr 10–May 1 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 6–Apr 3 (sow outdoors) | Jul 11–25 (sowing) |
| Onion (bulbing) | Feb 6–20 | Mar 20–Apr 3 (transplant) | – |
| Green onion / scallion | – | Mar 20–Apr 17 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Leek | Feb 6–20 | Apr 3–17 (transplant) | – |
| Garlic | – | – | Aug 22–Sep 19 (sowing) |
| Shallot | – | Mar 20–Apr 3 (transplant) | Aug 22–Sep 19 (sowing) |
| Potato | – | Apr 3–17 (transplant) | Jun 13–27 (transplant) |
| Sweet potato | – | May 22–Jun 5 (transplant) | – |
| Sweet corn | – | May 8–22 (sow outdoors) | – |
| Bean, bush (snap) | – | May 8–22 (sow outdoors) | – |
| Bean, pole | – | May 8–22 (sow outdoors) | – |
| Lima bean | – | May 15–29 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 22–Jun 12 (sow outdoors) | – |
| Cucumber | Apr 3–10 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Summer squash / zucchini | Apr 3–10 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Winter squash | Apr 3–10 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Pumpkin | – | May 8–22 (sow outdoors) | – |
| Watermelon | Apr 3–10 | May 15–29 (transplant) May 15–29 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 3–10 | May 15–29 (transplant) May 15–29 (sow outdoors) | – |
| Okra | Mar 20–Apr 3 | May 15–29 (transplant) May 15–29 (sow outdoors) | – |
| Celery | Feb 6–20 | May 8–15 (transplant) | – |
| Basil | Mar 20–Apr 3 | May 8–22 (transplant) May 8–22 (sow outdoors) | – |
| Cilantro | – | Apr 17–May 15 (sow outdoors) | Aug 8–22 (sowing) |
| Parsley | Feb 20–Mar 6 | Apr 17–May 1 (transplant) Apr 10–May 1 (sow outdoors) | – |
| Dill | – | May 1–15 (sow outdoors) | Aug 8–22 (sowing) |
| Sunflower | – | May 1–15 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 3–17 (transplant) | – |
| Rhubarb (crowns) | – | Apr 3–17 (transplant) | – |
| Strawberry (plants) | – | Apr 3–17 (transplant) | Jul 25–Aug 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: Glenns Ferry, ID (NOAA GHCN-Daily ID USC00103631), elevation 2,466 ft, 8.0 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Mtn Home, ID | 17 mi | May 2 | Oct 8 |
| Bruneau, ID | 23 mi | Apr 17 | Oct 17 |
| Hill City 1 W, ID | 24 mi | Jun 16 | Sep 6 |
The average last-frost dates of these stations span 61 days, a rough guide to local variation. See data sources & methods.
Frost questions for 83623
When is the last frost in 83623?
The average (50% chance) last spring freeze of 32°F for ZIP 83623 is May 1. For a more cautious planting date, use May 16, when only 1 year in 10 still sees a later freeze.
When is the first frost in 83623?
The average first fall freeze is October 3. In 1 year in 10 it comes by September 16.
What hardiness zone is 83623?
ZIP 83623 is in USDA zone 7a (0 to 5°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 83623 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
83633 83627 Hammett 83337 83314 Bliss 83648 Mountain Home AFB 83604 Bruneau 83647 Mountain Home 83322
Other ZIP codes in Elmore County
83337 83633 83647 83648 83716 All Elmore County frost dates · Idaho 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.