USDA Hardiness Zone 6b
Frost Dates for 15456 — Lemont Furnace, Pennsylvania
NOAA 1991–2020 normals from Uniontown 1 NE, PA (956 ft), 3 miles west.
Updated
In Lemont Furnace, the last spring frost (32°F) is around April 30 in half of years and has passed by May 18 in nine years out of ten. The first fall frost comes around October 18, as early as October 5 one year in ten, leaving a typical freeze-free season of 171 days (NOAA, Uniontown 1 NE, PA).
- Last spring frost
- April 30
- First fall frost
- October 18
- Growing season
- 171 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- November 30
- Last snow
- March 20
- Winters with snow
- 100%
- Snow per year
- 28.1"
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Lemont Furnace
Half of springs at Uniontown 1 NE, PA see their last 32°F night by April 30; only one in ten is past it by April 15, and one in ten still has one after May 18. Planting tender crops after May 7 leaves a 30% risk of a frost on them, after May 12 20%, and after May 18 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 70% of the 176 Pennsylvania stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 18 in half of years, as early as October 5 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 10 days later, around October 28; in spring the one-in-ten date for 28°F is May 6, 12 days before the 32°F one. The freeze-free season lasts 171 days in a typical year, shorter than at 57% of the 176 Pennsylvania stations; it reaches 191 days one year in ten and falls short of 149 one year in ten. On average 129 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 10 days longer, to about May 10, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 3 and March 11.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 25 | Apr 30 | May 3 | May 7 | May 10 | May 14 | May 18 | May 22 | May 27 |
| 32°F | Apr 15 | Apr 20 | Apr 24 | Apr 27 | Apr 30 | May 3 | May 7 | May 12 | May 18 |
| 28°F | Mar 31 | Apr 4 | Apr 9 | Apr 13 | Apr 17 | Apr 20 | Apr 25 | Apr 30 | May 6 |
| 24°F | Mar 18 | Mar 23 | Mar 28 | Mar 31 | Apr 2 | Apr 5 | Apr 8 | Apr 13 | Apr 18 |
| 20°F | Mar 3 | Mar 10 | Mar 16 | Mar 19 | Mar 23 | Mar 27 | Mar 31 | Apr 2 | Apr 7 |
| 16°F | Feb 21 | Feb 27 | Mar 3 | Mar 7 | Mar 11 | Mar 15 | Mar 19 | Mar 22 | Mar 28 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 12 | Oct 15 | Oct 20 |
| 32°F | Oct 5 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 30 |
| 28°F | Oct 14 | Oct 19 | Oct 23 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 10 |
| 24°F | Oct 25 | Oct 31 | Nov 1 | Nov 4 | Nov 6 | Nov 10 | Nov 13 | Nov 18 | Nov 24 |
| 20°F | Nov 3 | Nov 8 | Nov 12 | Nov 15 | Nov 19 | Nov 23 | Nov 28 | Dec 2 | Dec 10 |
| 16°F | Nov 12 | Nov 19 | Nov 25 | Nov 30 | Dec 3 | Dec 8 | Dec 14 | Dec 20 | Dec 27 |
Freeze probabilities 1991–2020 at Uniontown 1 NE, PA, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 15456 →Compare Lemont Furnace with another place →
Weather by month in Lemont Furnace
July is the warmest month at Uniontown 1 NE, PA, averaging 84°F by day and 62°F at night; January is the coldest at 40°F and 21°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 48% of years.
Warmth for growing adds up to 3,185 growing degree days a year (base 50°F), more than at 68% of the 176 Pennsylvania stations. 35% of them (1,112) have built up by the end of June, and July adds the most, 716. Precipitation totals 44.5 inches a year, most in June (4.8") and least in February (2.8"); May to September bring 48% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 40 | 21 | 3.3 | 100% | 26 | 8 |
| Feb | 43 | 23 | 2.8 | 100% | 24 | 9 |
| Mar | 51 | 29 | 3.7 | 100% | 21 | 36 |
| Apr | 64 | 38 | 3.8 | 98% | 10 | 142 |
| May | 73 | 48 | 4.4 | 48% | 1 | 347 |
| Jun | 81 | 57 | 4.8 | 0% | 0 | 570 |
| Jul | 84 | 62 | 4.8 | 0% | 0 | 716 |
| Aug | 83 | 60 | 3.6 | 0% | 0 | 673 |
| Sep | 78 | 53 | 3.6 | 3% | <1 | 460 |
| Oct | 66 | 41 | 3.2 | 92% | 7 | 174 |
| Nov | 54 | 32 | 3.2 | 100% | 17 | 38 |
| Dec | 44 | 26 | 3.3 | 100% | 24 | 13 |
Monthly normals 1991–2020 at Uniontown 1 NE, PA (956 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Connellsville 2 SSW, PA, 6 miles northeast of Lemont Furnace, has a last frost 8 days earlier (April 22), a first frost 9 days later (October 27), a season 16 days longer.
When it snows in Lemont Furnace, Pennsylvania
The first measurable snow (0.1 inch or more) in Lemont Furnace usually arrives around November 30, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Uniontown 1 NE, PA, 3.2 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 41 days after the last snow.
Planting calendar for 15456
| When | What to do |
|---|---|
| February 19 – March 5 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 5 – March 19 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 2 – April 16 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 30 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 26 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 4 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 18 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 15456 is 3 miles from Uniontown 1 NE, PA, which stands at 956 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 15401 (Uniontown). The 2023 USDA Plant Hardiness Zone Map lists ZIP 15456 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Pennsylvania →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.