Fall in zone 6aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 83637 (Lowman, 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, Lowman, ID (23 miles away).
- Average last spring frostJun 650% chance of a 32°F freeze after this date
- Average first fall frostSep 450% chance of a 32°F freeze by this date
- Growing season (frost-free)87 daysmedian, 32°F threshold
- USDA hardiness zone6a-10 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
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 83637 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 18 |
| 50% (the "average" last frost) | Jun 6 |
| 10% (cautious: only 1 year in 10 freezes later) | Jul 1 |
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 19 |
| 50% (the "average" first frost) | Sep 4 |
| 90% (late: most years have frozen by now) | Sep 24 |
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 6 | Sep 4 |
| 28°F (hard freeze) | May 15 | Sep 23 |
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 83637
Dates count from your average last spring frost (Jun 6) and first fall frost (Sep 4). 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 11–25 | Jun 13–27 (transplant) | – |
| Pepper (sweet and hot) | Mar 28–Apr 11 | Jun 20–Jul 4 (transplant) | – |
| Eggplant | Mar 28–Apr 11 | Jun 20–Jul 4 (transplant) | – |
| Tomatillo | Apr 11–25 | Jun 13–27 (transplant) | – |
| Lettuce | Apr 11–25 | May 16–Jun 6 (transplant) May 9–Jun 20 (sow outdoors) | Jul 10–31 (transplant) Jun 26–Jul 24 (sowing) |
| Spinach | – | Apr 25–May 16 (sow outdoors) | Jul 10–31 (sowing) |
| Kale | Apr 11–25 | May 9–23 (transplant) May 9–23 (sow outdoors) | Jun 12–Jul 10 (transplant) May 29–Jun 26 (sowing) |
| Collards | Apr 11–25 | May 9–Jun 6 (transplant) May 9–Jun 6 (sow outdoors) | Jun 12–Jul 10 (transplant) |
| Broccoli | Mar 28–Apr 11 | May 9–23 (transplant) | May 29–Jun 26 (transplant) |
| Cabbage | Mar 28–Apr 11 | May 9–23 (transplant) | May 29–Jun 26 (transplant) |
| Cauliflower | Mar 28–Apr 11 | May 23–Jun 6 (transplant) | – |
| Brussels sprouts | Mar 14–28 | May 9–23 (transplant) | – |
| Kohlrabi | Apr 11–25 | May 9–23 (transplant) May 9–23 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Bok choy / Asian greens | – | May 9–23 (sow outdoors) | Jul 10–24 (sowing) |
| Arugula | – | May 9–Jun 6 (sow outdoors) | Jul 10–Aug 7 (sowing) |
| Mustard greens | – | May 9–30 (sow outdoors) | Jul 10–24 (sowing) |
| Swiss chard | Apr 25–May 9 | May 23–Jun 13 (transplant) May 23–Jun 20 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Beet | – | May 9–Jun 6 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Carrot | – | May 16–Jun 13 (sow outdoors) | – |
| Radish | – | May 2–Jun 13 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Turnip | – | May 9–30 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Parsnip | – | May 16–Jun 6 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 11–May 9 (sow outdoors) | Jun 12–26 (sowing) |
| Onion (bulbing) | Mar 14–28 | Apr 25–May 9 (transplant) | – |
| Green onion / scallion | – | Apr 25–May 23 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Leek | Mar 14–28 | May 9–23 (transplant) | – |
| Garlic | – | – | Jul 24–Aug 21 (sowing) |
| Shallot | – | Apr 25–May 9 (transplant) | Jul 24–Aug 21 (sowing) |
| Potato | – | May 9–23 (transplant) | – |
| Sweet potato | – | Jun 27–Jul 11 (transplant) | – |
| Sweet corn | – | Jun 13–27 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 13–27 (sow outdoors) | – |
| Bean, pole | – | Jun 13–27 (sow outdoors) | – |
| Lima bean | – | Jun 20–Jul 4 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 27–Jul 18 (sow outdoors) | – |
| Cucumber | May 9–16 | Jun 13–27 (transplant) Jun 13–27 (sow outdoors) | – |
| Summer squash / zucchini | May 9–16 | Jun 13–27 (transplant) Jun 13–27 (sow outdoors) | – |
| Winter squash | May 9–16 | Jun 13–27 (transplant) Jun 13–27 (sow outdoors) | – |
| Pumpkin | – | Jun 13–27 (sow outdoors) | – |
| Watermelon | May 9–16 | Jun 20–Jul 4 (transplant) Jun 20–Jul 4 (sow outdoors) | – |
| Cantaloupe / muskmelon | May 9–16 | Jun 20–Jul 4 (transplant) Jun 20–Jul 4 (sow outdoors) | – |
| Okra | Apr 25–May 9 | Jun 20–Jul 4 (transplant) Jun 20–Jul 4 (sow outdoors) | – |
| Celery | Mar 14–28 | Jun 13–20 (transplant) | – |
| Basil | Apr 25–May 9 | Jun 13–27 (transplant) Jun 13–27 (sow outdoors) | – |
| Cilantro | – | May 23–Jun 20 (sow outdoors) | Jul 10–24 (sowing) |
| Parsley | Mar 28–Apr 11 | May 23–Jun 6 (transplant) May 16–Jun 6 (sow outdoors) | – |
| Dill | – | Jun 6–20 (sow outdoors) | Jul 10–24 (sowing) |
| Sunflower | – | Jun 6–20 (sow outdoors) | – |
| Asparagus (crowns) | – | May 9–23 (transplant) | – |
| Rhubarb (crowns) | – | May 9–23 (transplant) | – |
| Strawberry (plants) | – | May 9–23 (transplant) | Jun 26–Jul 24 (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: Lowman, ID (NOAA GHCN-Daily ID USC00105414), elevation 3,920 ft, 23.1 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Idaho City, ID | 38 mi | Jun 17 | Sep 5 |
| Garden Valley, ID | 40 mi | Jun 1 | Sep 10 |
| Middle Fork Lodge, ID | 43 mi | May 21 | Sep 18 |
The average last-frost dates of these stations span 27 days, a rough guide to local variation. See data sources & methods.
Frost questions for 83637
When is the last frost in 83637?
The average (50% chance) last spring freeze of 32°F for ZIP 83637 is June 6. For a more cautious planting date, use July 1, when only 1 year in 10 still sees a later freeze.
When is the first frost in 83637?
The average first fall freeze is September 4. In 1 year in 10 it comes by August 19.
What hardiness zone is 83637?
ZIP 83637 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 83637 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
83716 Robie Creek 83278 Stanley 83227 Clayton 83631 Idaho City 83622 Garden Valley 83340 Ketchum 83666 Placerville 83327 Fairfield
Other ZIP codes in Boise County
83602 83622 83629 83631 83666 All Boise County frost dates · Idaho 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.