Fall in zone 6bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 15139 (Oakmont, 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, Acmetonia Lock 3, PA (1 miles away).
- Average last spring frostApr 1650% chance of a 32°F freeze after this date
- Average first fall frostNov 150% chance of a 32°F freeze by this date
- Growing season (frost-free)197 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 15139 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
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 1: 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 31 |
| 50% (the "average" last frost) | Apr 16 |
| 10% (cautious: only 1 year in 10 freezes later) | May 4 |
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 18 |
| 50% (the "average" first frost) | Nov 1 |
| 90% (late: most years have frozen by now) | Nov 13 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 29 | Oct 20 |
| 32°F (freeze) | Apr 16 | Nov 1 |
| 28°F (hard freeze) | Apr 3 | Nov 11 |
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 15139
Dates count from your average last spring frost (Apr 16) and first fall frost (Nov 1). 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 19–Mar 5 | Apr 23–May 7 (transplant) | – |
| Pepper (sweet and hot) | Feb 5–19 | Apr 30–May 14 (transplant) | – |
| Eggplant | Feb 5–19 | Apr 30–May 14 (transplant) | – |
| Tomatillo | Feb 19–Mar 5 | Apr 23–May 7 (transplant) | – |
| Lettuce | Feb 19–Mar 5 | Mar 26–Apr 16 (transplant) Mar 19–Apr 30 (sow outdoors) | Sep 6–27 (transplant) Aug 23–Sep 20 (sowing) |
| Spinach | – | Mar 5–26 (sow outdoors) | Sep 6–27 (sowing) |
| Kale | Feb 19–Mar 5 | Mar 19–Apr 2 (transplant) Mar 19–Apr 2 (sow outdoors) | Aug 9–Sep 6 (transplant) Jul 26–Aug 23 (sowing) |
| Collards | Feb 19–Mar 5 | Mar 19–Apr 16 (transplant) Mar 19–Apr 16 (sow outdoors) | Aug 9–Sep 6 (transplant) Jul 26–Aug 23 (sowing) |
| Broccoli | Feb 5–19 | Mar 19–Apr 2 (transplant) | Jul 26–Aug 23 (transplant) |
| Cabbage | Feb 5–19 | Mar 19–Apr 2 (transplant) | Jul 26–Aug 23 (transplant) |
| Cauliflower | Feb 5–19 | Apr 2–16 (transplant) | Jul 26–Aug 23 (transplant) |
| Brussels sprouts | Jan 22–Feb 5 | Mar 19–Apr 2 (transplant) | Jul 12–Aug 2 (transplant) |
| Kohlrabi | Feb 19–Mar 5 | Mar 19–Apr 2 (transplant) Mar 19–Apr 2 (sow outdoors) | Aug 23–Sep 6 (sowing) |
| Bok choy / Asian greens | – | Mar 19–Apr 2 (sow outdoors) | Sep 6–20 (sowing) |
| Arugula | – | Mar 19–Apr 16 (sow outdoors) | Sep 6–Oct 4 (sowing) |
| Mustard greens | – | Mar 19–Apr 9 (sow outdoors) | Sep 6–20 (sowing) |
| Swiss chard | Mar 5–19 | Apr 2–23 (transplant) Apr 2–30 (sow outdoors) | Aug 23–Sep 6 (sowing) |
| Beet | – | Mar 19–Apr 16 (sow outdoors) | Aug 23–Sep 6 (sowing) |
| Carrot | – | Mar 26–Apr 23 (sow outdoors) | Aug 9–23 (sowing) |
| Radish | – | Mar 12–Apr 23 (sow outdoors) | Sep 20–Oct 4 (sowing) |
| Turnip | – | Mar 19–Apr 9 (sow outdoors) | Aug 23–Sep 6 (sowing) |
| Parsnip | – | Mar 26–Apr 16 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 19–Mar 19 (sow outdoors) | Aug 9–23 (sowing) |
| Onion (bulbing) | Jan 22–Feb 5 | Mar 5–19 (transplant) | – |
| Green onion / scallion | – | Mar 5–Apr 2 (sow outdoors) | Aug 23–Sep 6 (sowing) |
| Leek | Jan 22–Feb 5 | Mar 19–Apr 2 (transplant) | – |
| Garlic | – | – | Sep 20–Oct 18 (sowing) |
| Shallot | – | Mar 5–19 (transplant) | Sep 20–Oct 18 (sowing) |
| Potato | – | Mar 19–Apr 2 (transplant) | Jul 12–26 (transplant) |
| Sweet potato | – | May 7–21 (transplant) | – |
| Sweet corn | – | Apr 23–May 7 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 23–May 7 (sow outdoors) | – |
| Bean, pole | – | Apr 23–May 7 (sow outdoors) | – |
| Lima bean | – | Apr 30–May 14 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 7–28 (sow outdoors) | – |
| Cucumber | Mar 19–26 | Apr 23–May 7 (transplant) Apr 23–May 7 (sow outdoors) | – |
| Summer squash / zucchini | Mar 19–26 | Apr 23–May 7 (transplant) Apr 23–May 7 (sow outdoors) | – |
| Winter squash | Mar 19–26 | Apr 23–May 7 (transplant) Apr 23–May 7 (sow outdoors) | – |
| Pumpkin | – | Apr 23–May 7 (sow outdoors) | – |
| Watermelon | Mar 19–26 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 19–26 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | – |
| Okra | Mar 5–19 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | – |
| Celery | Jan 22–Feb 5 | Apr 23–30 (transplant) | – |
| Basil | Mar 5–19 | Apr 23–May 7 (transplant) Apr 23–May 7 (sow outdoors) | – |
| Cilantro | – | Apr 2–30 (sow outdoors) | Sep 6–20 (sowing) |
| Parsley | Feb 5–19 | Apr 2–16 (transplant) Mar 26–Apr 16 (sow outdoors) | – |
| Dill | – | Apr 16–30 (sow outdoors) | Sep 6–20 (sowing) |
| Sunflower | – | Apr 16–30 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 19–Apr 2 (transplant) | – |
| Rhubarb (crowns) | – | Mar 19–Apr 2 (transplant) | – |
| Strawberry (plants) | – | Mar 19–Apr 2 (transplant) | Aug 23–Sep 20 (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: Acmetonia Lock 3, PA (NOAA GHCN-Daily ID USC00360022), elevation 748 ft, 1.4 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%) |
|---|---|---|---|
| Natrona Lock 4, PA | 9 mi | Apr 16 | Nov 2 |
| Braddock Lock 2, PA | 9 mi | Apr 5 | Nov 10 |
| Murrysville 2 SW, PA | 10 mi | Apr 22 | Oct 25 |
The average last-frost dates of these stations span 17 days, a rough guide to local variation. See data sources & methods.
Frost questions for 15139
When is the last frost in 15139?
The average (50% chance) last spring freeze of 32°F for ZIP 15139 is April 16. For a more cautious planting date, use May 4, when only 1 year in 10 still sees a later freeze.
When is the first frost in 15139?
The average first fall freeze is November 1. In 1 year in 10 it comes by October 18.
What hardiness zone is 15139?
ZIP 15139 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 15139 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
15147 Plum 15238 Fox Chapel 15049 Harwick 15144 Springdale 15051 15215 Fox Chapel 15024 Cheswick 15075
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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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.