Fall in zone 6aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 49221 (Adrian, MI)
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, Adrian Lenawee Co AP, MI (2 miles away).
- Average last spring frostApr 2750% chance of a 32°F freeze after this date
- Average first fall frostOct 2050% chance of a 32°F freeze by this date
- Growing season (frost-free)173 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 49221 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 early May.
Fertilizer window
Lawn region: North (cool-season). 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.
Your average first frost is Oct 20: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
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 13 |
| 50% (the "average" last frost) | Apr 27 |
| 10% (cautious: only 1 year in 10 freezes later) | May 14 |
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) | Oct 4 |
| 50% (the "average" first frost) | Oct 20 |
| 90% (late: most years have frozen by now) | Nov 1 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 7 | Oct 6 |
| 32°F (freeze) | Apr 27 | Oct 20 |
| 28°F (hard freeze) | Apr 16 | Oct 31 |
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 49221
Dates count from your average last spring frost (Apr 27) and first fall frost (Oct 20). 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 2–16 | May 4–18 (transplant) | – |
| Pepper (sweet and hot) | Feb 16–Mar 2 | May 11–25 (transplant) | – |
| Eggplant | Feb 16–Mar 2 | May 11–25 (transplant) | – |
| Tomatillo | Mar 2–16 | May 4–18 (transplant) | – |
| Lettuce | Mar 2–16 | Apr 6–27 (transplant) Mar 30–May 11 (sow outdoors) | Aug 25–Sep 15 (transplant) Aug 11–Sep 8 (sowing) |
| Spinach | – | Mar 16–Apr 6 (sow outdoors) | Aug 25–Sep 15 (sowing) |
| Kale | Mar 2–16 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | Jul 28–Aug 25 (transplant) Jul 14–Aug 11 (sowing) |
| Collards | Mar 2–16 | Mar 30–Apr 27 (transplant) Mar 30–Apr 27 (sow outdoors) | Jul 28–Aug 25 (transplant) Jul 14–Aug 11 (sowing) |
| Broccoli | Feb 16–Mar 2 | Mar 30–Apr 13 (transplant) | Jul 14–Aug 11 (transplant) |
| Cabbage | Feb 16–Mar 2 | Mar 30–Apr 13 (transplant) | Jul 14–Aug 11 (transplant) |
| Cauliflower | Feb 16–Mar 2 | Apr 13–27 (transplant) | Jul 14–Aug 11 (transplant) |
| Brussels sprouts | Feb 2–16 | Mar 30–Apr 13 (transplant) | Jun 30–Jul 21 (transplant) |
| Kohlrabi | Mar 2–16 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | Aug 11–25 (sowing) |
| Bok choy / Asian greens | – | Mar 30–Apr 13 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Arugula | – | Mar 30–Apr 27 (sow outdoors) | Aug 25–Sep 22 (sowing) |
| Mustard greens | – | Mar 30–Apr 20 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Swiss chard | Mar 16–30 | Apr 13–May 4 (transplant) Apr 13–May 11 (sow outdoors) | Aug 11–25 (sowing) |
| Beet | – | Mar 30–Apr 27 (sow outdoors) | Aug 11–25 (sowing) |
| Carrot | – | Apr 6–May 4 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Radish | – | Mar 23–May 4 (sow outdoors) | Sep 8–22 (sowing) |
| Turnip | – | Mar 30–Apr 20 (sow outdoors) | Aug 11–25 (sowing) |
| Parsnip | – | Apr 6–27 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 2–30 (sow outdoors) | Jul 28–Aug 11 (sowing) |
| Onion (bulbing) | Feb 2–16 | Mar 16–30 (transplant) | – |
| Green onion / scallion | – | Mar 16–Apr 13 (sow outdoors) | Aug 11–25 (sowing) |
| Leek | Feb 2–16 | Mar 30–Apr 13 (transplant) | – |
| Garlic | – | – | Sep 8–Oct 6 (sowing) |
| Shallot | – | Mar 16–30 (transplant) | Sep 8–Oct 6 (sowing) |
| Potato | – | Mar 30–Apr 13 (transplant) | Jun 30–Jul 14 (transplant) |
| Sweet potato | – | May 18–Jun 1 (transplant) | – |
| Sweet corn | – | May 4–18 (sow outdoors) | – |
| Bean, bush (snap) | – | May 4–18 (sow outdoors) | – |
| Bean, pole | – | May 4–18 (sow outdoors) | – |
| Lima bean | – | May 11–25 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 18–Jun 8 (sow outdoors) | – |
| Cucumber | Mar 30–Apr 6 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Summer squash / zucchini | Mar 30–Apr 6 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Winter squash | Mar 30–Apr 6 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Pumpkin | – | May 4–18 (sow outdoors) | – |
| Watermelon | Mar 30–Apr 6 | May 11–25 (transplant) May 11–25 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 30–Apr 6 | May 11–25 (transplant) May 11–25 (sow outdoors) | – |
| Okra | Mar 16–30 | May 11–25 (transplant) May 11–25 (sow outdoors) | – |
| Celery | Feb 2–16 | May 4–11 (transplant) | – |
| Basil | Mar 16–30 | May 4–18 (transplant) May 4–18 (sow outdoors) | – |
| Cilantro | – | Apr 13–May 11 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Parsley | Feb 16–Mar 2 | Apr 13–27 (transplant) Apr 6–27 (sow outdoors) | – |
| Dill | – | Apr 27–May 11 (sow outdoors) | Aug 25–Sep 8 (sowing) |
| Sunflower | – | Apr 27–May 11 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 30–Apr 13 (transplant) | – |
| Rhubarb (crowns) | – | Mar 30–Apr 13 (transplant) | – |
| Strawberry (plants) | – | Mar 30–Apr 13 (transplant) | Aug 11–Sep 8 (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: Adrian Lenawee Co AP, MI (NOAA GHCN-Daily ID USW00004847), elevation 796 ft, 2.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Adrian 2 NNE, MI | 3 mi | May 1 | Oct 15 |
| Tipton 2WNW, MI | 9 mi | May 5 | Oct 10 |
| Tecumseh, MI | 10 mi | May 3 | Oct 13 |
The average last-frost dates of these stations span 9 days, a rough guide to local variation. See data sources & methods.
Frost questions for 49221
When is the last frost in 49221?
The average (50% chance) last spring freeze of 32°F for ZIP 49221 is April 27. For a more cautious planting date, use May 14, when only 1 year in 10 still sees a later freeze.
When is the first frost in 49221?
The average first fall freeze is October 20. In 1 year in 10 it comes by October 4.
What hardiness zone is 49221?
ZIP 49221 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 49221 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
49268 49235 Clayton 49287 49279 49265 Onsted 49289 49286 Tecumseh 49248 Jasper
Other ZIP codes in Lenawee County
49220 49228 49229 49235 49236 49238 49247 49248 49253 49256 49265 49268 49276 49279 49286 49287 49289 All Lenawee County frost dates · Michigan 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.