Fall in zone 6bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 66021 (Edgerton, KS)
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, Olathe Johnson Co AP, KS (8 miles away).
- Average last spring frostApr 1350% chance of a 32°F freeze after this date
- Average first fall frostOct 2450% chance of a 32°F freeze by this date
- Growing season (frost-free)193 daysmedian, 32°F threshold
- USDA hardiness zone6b-5 to 0°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
55°F 55°F or warmer
24-hour average · latest 54°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Ku-Nesa (23 mi), Powell Gardens (53 mi).
4-inch depth
64°F 55°F or warmer
24-hour average · latest 63°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Ku-Nesa (23 mi), Powell Gardens (53 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 66021 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 64°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: Transition zone. Timing only; always follow the product label.
- Bermudagrass (warm-season): Spring: Several weeks after the lawn is fully green (April–May) (about May 29 here, using green-up about 3–4 weeks after your average last frost); Summer: Every 4–6 weeks through mid-August (heaviest feeder of the group); Late: Light, low-nitrogen/high-potassium feeding about 4 weeks before first frost, or skip. Avoid: Heavy late-fall nitrogen (linked to spring dead spot).
- Tall fescue (cool-season): Early fall: September (main feeding); Late fall: November, while still green; Late winter: Optional light feeding February–March. Avoid: Feeding after mid-spring and through summer in the transition zone (stress and brown patch).
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 24: 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) | Mar 30 |
| 50% (the "average" last frost) | Apr 13 |
| 10% (cautious: only 1 year in 10 freezes later) | Apr 29 |
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 10 |
| 50% (the "average" first frost) | Oct 24 |
| 90% (late: most years have frozen by now) | Nov 4 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 23 | Oct 15 |
| 32°F (freeze) | Apr 13 | Oct 24 |
| 28°F (hard freeze) | Apr 3 | Nov 2 |
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 66021
Dates count from your average last spring frost (Apr 13) and first fall frost (Oct 24). 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 | Feb 16–Mar 2 | Apr 20–May 4 (transplant) | – |
| Pepper (sweet and hot) | Feb 2–16 | Apr 27–May 11 (transplant) | – |
| Eggplant | Feb 2–16 | Apr 27–May 11 (transplant) | – |
| Tomatillo | Feb 16–Mar 2 | Apr 20–May 4 (transplant) | – |
| Lettuce | Feb 16–Mar 2 | Mar 23–Apr 13 (transplant) Mar 16–Apr 27 (sow outdoors) | Aug 29–Sep 19 (transplant) Aug 15–Sep 12 (sowing) |
| Spinach | – | Mar 2–23 (sow outdoors) | Aug 29–Sep 19 (sowing) |
| Kale | Feb 16–Mar 2 | Mar 16–30 (transplant) Mar 16–30 (sow outdoors) | Aug 1–29 (transplant) Jul 18–Aug 15 (sowing) |
| Collards | Feb 16–Mar 2 | Mar 16–Apr 13 (transplant) Mar 16–Apr 13 (sow outdoors) | Aug 1–29 (transplant) Jul 18–Aug 15 (sowing) |
| Broccoli | Feb 2–16 | Mar 16–30 (transplant) | Jul 18–Aug 15 (transplant) |
| Cabbage | Feb 2–16 | Mar 16–30 (transplant) | Jul 18–Aug 15 (transplant) |
| Cauliflower | Feb 2–16 | Mar 30–Apr 13 (transplant) | Jul 18–Aug 15 (transplant) |
| Brussels sprouts | Jan 19–Feb 2 | Mar 16–30 (transplant) | Jul 4–25 (transplant) |
| Kohlrabi | Feb 16–Mar 2 | Mar 16–30 (transplant) Mar 16–30 (sow outdoors) | Aug 15–29 (sowing) |
| Bok choy / Asian greens | – | Mar 16–30 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Arugula | – | Mar 16–Apr 13 (sow outdoors) | Aug 29–Sep 26 (sowing) |
| Mustard greens | – | Mar 16–Apr 6 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Swiss chard | Mar 2–16 | Mar 30–Apr 20 (transplant) Mar 30–Apr 27 (sow outdoors) | Aug 15–29 (sowing) |
| Beet | – | Mar 16–Apr 13 (sow outdoors) | Aug 15–29 (sowing) |
| Carrot | – | Mar 23–Apr 20 (sow outdoors) | Aug 1–15 (sowing) |
| Radish | – | Mar 9–Apr 20 (sow outdoors) | Sep 12–26 (sowing) |
| Turnip | – | Mar 16–Apr 6 (sow outdoors) | Aug 15–29 (sowing) |
| Parsnip | – | Mar 23–Apr 13 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 16–Mar 16 (sow outdoors) | Aug 1–15 (sowing) |
| Onion (bulbing) | Jan 19–Feb 2 | Mar 2–16 (transplant) | – |
| Green onion / scallion | – | Mar 2–30 (sow outdoors) | Aug 15–29 (sowing) |
| Leek | Jan 19–Feb 2 | Mar 16–30 (transplant) | – |
| Garlic | – | – | Sep 12–Oct 10 (sowing) |
| Shallot | – | Mar 2–16 (transplant) | Sep 12–Oct 10 (sowing) |
| Potato | – | Mar 16–30 (transplant) | Jul 4–18 (transplant) |
| Sweet potato | – | May 4–18 (transplant) | – |
| Sweet corn | – | Apr 20–May 4 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 20–May 4 (sow outdoors) | – |
| Bean, pole | – | Apr 20–May 4 (sow outdoors) | – |
| Lima bean | – | Apr 27–May 11 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 4–25 (sow outdoors) | – |
| Cucumber | Mar 16–23 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | – |
| Summer squash / zucchini | Mar 16–23 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | – |
| Winter squash | Mar 16–23 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | – |
| Pumpkin | – | Apr 20–May 4 (sow outdoors) | – |
| Watermelon | Mar 16–23 | Apr 27–May 11 (transplant) Apr 27–May 11 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 16–23 | Apr 27–May 11 (transplant) Apr 27–May 11 (sow outdoors) | – |
| Okra | Mar 2–16 | Apr 27–May 11 (transplant) Apr 27–May 11 (sow outdoors) | – |
| Celery | Jan 19–Feb 2 | Apr 20–27 (transplant) | – |
| Basil | Mar 2–16 | Apr 20–May 4 (transplant) Apr 20–May 4 (sow outdoors) | – |
| Cilantro | – | Mar 30–Apr 27 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Parsley | Feb 2–16 | Mar 30–Apr 13 (transplant) Mar 23–Apr 13 (sow outdoors) | – |
| Dill | – | Apr 13–27 (sow outdoors) | Aug 29–Sep 12 (sowing) |
| Sunflower | – | Apr 13–27 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 16–30 (transplant) | – |
| Rhubarb (crowns) | – | Mar 16–30 (transplant) | – |
| Strawberry (plants) | – | Mar 16–30 (transplant) | Aug 15–Sep 12 (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.
Plants that do well here
Kansas has a university or garden plant program: Prairie Star Flowers. Plant frost-tender annuals after April 13 here (the average last frost). Not affiliated with the program.
Where these numbers come from
Station: Olathe Johnson Co AP, KS (NOAA GHCN-Daily ID USW00093909), elevation 1,087 ft, 8.1 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Hillsdale Lake, KS | 9 mi | Apr 9 | Oct 31 |
| Paola, KS | 13 mi | Apr 13 | Oct 21 |
| Olathe Johnson Co Exec AP, KS | 16 mi | Apr 8 | Oct 29 |
The average last-frost dates of these stations span 5 days, a rough guide to local variation. See data sources & methods.
Frost questions for 66021
When is the last frost in 66021?
The average (50% chance) last spring freeze of 32°F for ZIP 66021 is April 13. For a more cautious planting date, use April 29, when only 1 year in 10 still sees a later freeze.
When is the first frost in 66021?
The average first fall freeze is October 24. In 1 year in 10 it comes by October 10.
What hardiness zone is 66021?
ZIP 66021 is in USDA zone 6b (-5 to 0°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 66021 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
66030 Gardner 66092 Wellsville 66031 Gardner 66083 Spring Hill 66025 Eudora 66061 Olathe 66006 Baldwin City 66062 Olathe
Other ZIP codes in Johnson County
66018 66030 66031 66061 66062 66085 66202 66203 66204 66205 66206 66207 66208 66209 66210 66211 66212 66213 66214 66215 66216 66217 66218 66219 All Johnson County frost dates · Kansas 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.