Fall in zone 6bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 15239 (Plum, PA)
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, Murrysville 2 SW, PA (5 miles away).
- Average last spring frostApr 2250% chance of a 32°F freeze after this date
- Average first fall frostOct 2550% chance of a 32°F freeze by this date
- Growing season (frost-free)186 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
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 15239 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 25: 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 7 |
| 50% (the "average" last frost) | Apr 22 |
| 10% (cautious: only 1 year in 10 freezes later) | May 12 |
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 25 |
| 90% (late: most years have frozen by now) | Nov 6 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 5 | Oct 13 |
| 32°F (freeze) | Apr 22 | Oct 25 |
| 28°F (hard freeze) | Apr 7 | Nov 5 |
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 15239
Dates count from your average last spring frost (Apr 22) and first fall frost (Oct 25). 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 25–Mar 11 | Apr 29–May 13 (transplant) | – |
| Pepper (sweet and hot) | Feb 11–25 | May 6–20 (transplant) | – |
| Eggplant | Feb 11–25 | May 6–20 (transplant) | – |
| Tomatillo | Feb 25–Mar 11 | Apr 29–May 13 (transplant) | – |
| Lettuce | Feb 25–Mar 11 | Apr 1–22 (transplant) Mar 25–May 6 (sow outdoors) | Aug 30–Sep 20 (transplant) Aug 16–Sep 13 (sowing) |
| Spinach | – | Mar 11–Apr 1 (sow outdoors) | Aug 30–Sep 20 (sowing) |
| Kale | Feb 25–Mar 11 | Mar 25–Apr 8 (transplant) Mar 25–Apr 8 (sow outdoors) | Aug 2–30 (transplant) Jul 19–Aug 16 (sowing) |
| Collards | Feb 25–Mar 11 | Mar 25–Apr 22 (transplant) Mar 25–Apr 22 (sow outdoors) | Aug 2–30 (transplant) Jul 19–Aug 16 (sowing) |
| Broccoli | Feb 11–25 | Mar 25–Apr 8 (transplant) | Jul 19–Aug 16 (transplant) |
| Cabbage | Feb 11–25 | Mar 25–Apr 8 (transplant) | Jul 19–Aug 16 (transplant) |
| Cauliflower | Feb 11–25 | Apr 8–22 (transplant) | Jul 19–Aug 16 (transplant) |
| Brussels sprouts | Jan 28–Feb 11 | Mar 25–Apr 8 (transplant) | Jul 5–26 (transplant) |
| Kohlrabi | Feb 25–Mar 11 | Mar 25–Apr 8 (transplant) Mar 25–Apr 8 (sow outdoors) | Aug 16–30 (sowing) |
| Bok choy / Asian greens | – | Mar 25–Apr 8 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Arugula | – | Mar 25–Apr 22 (sow outdoors) | Aug 30–Sep 27 (sowing) |
| Mustard greens | – | Mar 25–Apr 15 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Swiss chard | Mar 11–25 | Apr 8–29 (transplant) Apr 8–May 6 (sow outdoors) | Aug 16–30 (sowing) |
| Beet | – | Mar 25–Apr 22 (sow outdoors) | Aug 16–30 (sowing) |
| Carrot | – | Apr 1–29 (sow outdoors) | Aug 2–16 (sowing) |
| Radish | – | Mar 18–Apr 29 (sow outdoors) | Sep 13–27 (sowing) |
| Turnip | – | Mar 25–Apr 15 (sow outdoors) | Aug 16–30 (sowing) |
| Parsnip | – | Apr 1–22 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 25–Mar 25 (sow outdoors) | Aug 2–16 (sowing) |
| Onion (bulbing) | Jan 28–Feb 11 | Mar 11–25 (transplant) | – |
| Green onion / scallion | – | Mar 11–Apr 8 (sow outdoors) | Aug 16–30 (sowing) |
| Leek | Jan 28–Feb 11 | Mar 25–Apr 8 (transplant) | – |
| Garlic | – | – | Sep 13–Oct 11 (sowing) |
| Shallot | – | Mar 11–25 (transplant) | Sep 13–Oct 11 (sowing) |
| Potato | – | Mar 25–Apr 8 (transplant) | Jul 5–19 (transplant) |
| Sweet potato | – | May 13–27 (transplant) | – |
| Sweet corn | – | Apr 29–May 13 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 29–May 13 (sow outdoors) | – |
| Bean, pole | – | Apr 29–May 13 (sow outdoors) | – |
| Lima bean | – | May 6–20 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 13–Jun 3 (sow outdoors) | – |
| Cucumber | Mar 25–Apr 1 | Apr 29–May 13 (transplant) Apr 29–May 13 (sow outdoors) | – |
| Summer squash / zucchini | Mar 25–Apr 1 | Apr 29–May 13 (transplant) Apr 29–May 13 (sow outdoors) | – |
| Winter squash | Mar 25–Apr 1 | Apr 29–May 13 (transplant) Apr 29–May 13 (sow outdoors) | – |
| Pumpkin | – | Apr 29–May 13 (sow outdoors) | – |
| Watermelon | Mar 25–Apr 1 | May 6–20 (transplant) May 6–20 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 25–Apr 1 | May 6–20 (transplant) May 6–20 (sow outdoors) | – |
| Okra | Mar 11–25 | May 6–20 (transplant) May 6–20 (sow outdoors) | – |
| Celery | Jan 28–Feb 11 | Apr 29–May 6 (transplant) | – |
| Basil | Mar 11–25 | Apr 29–May 13 (transplant) Apr 29–May 13 (sow outdoors) | – |
| Cilantro | – | Apr 8–May 6 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Parsley | Feb 11–25 | Apr 8–22 (transplant) Apr 1–22 (sow outdoors) | – |
| Dill | – | Apr 22–May 6 (sow outdoors) | Aug 30–Sep 13 (sowing) |
| Sunflower | – | Apr 22–May 6 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 25–Apr 8 (transplant) | – |
| Rhubarb (crowns) | – | Mar 25–Apr 8 (transplant) | – |
| Strawberry (plants) | – | Mar 25–Apr 8 (transplant) | Aug 16–Sep 13 (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: Murrysville 2 SW, PA (NOAA GHCN-Daily ID USC00366111), elevation 860 ft, 5.0 miles from the ZIP's center point. NOAA completeness flag: E (estimated from nearby stations).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Acmetonia Lock 3, PA | 5 mi | Apr 16 | Nov 1 |
| Natrona Lock 4, PA | 9 mi | Apr 16 | Nov 2 |
| Braddock Lock 2, PA | 9 mi | Apr 5 | Nov 10 |
The average last-frost dates of these stations span 17 days, a rough guide to local variation. See data sources & methods.
Frost questions for 15239
When is the last frost in 15239?
The average (50% chance) last spring freeze of 32°F for ZIP 15239 is April 22. For a more cautious planting date, use May 12, when only 1 year in 10 still sees a later freeze.
When is the first frost in 15239?
The average first fall freeze is October 25. In 1 year in 10 it comes by October 10.
What hardiness zone is 15239?
ZIP 15239 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 15239 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
15668 Murrysville 15146 Monroeville 15235 Churchill 15144 Springdale 15147 Plum 15068 Lower Burrell 15140 Pitcairn 15139 Oakmont
Other ZIP codes in Allegheny County
15006 15007 15014 15015 15017 15018 15020 15024 15025 15028 15030 15031 15034 15035 15037 15044 15045 15046 15047 15049 15051 15056 15064 15065 All Allegheny County frost dates · Pennsylvania 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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- Weekly yard to-dos
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.