USDA Hardiness Zone 6a
Frost Dates for 15658 — Ligonier, Pennsylvania
NOAA 1991–2020 normals from Laurel Mountain, PA (2,760 ft), 4 miles southeast.
Updated
In Ligonier, the last spring frost (32°F) is around April 26 in half of years and has passed by May 13 in nine years out of ten. The first fall frost comes around October 17, as early as October 4 one year in ten, leaving a typical freeze-free season of 172 days (NOAA, Laurel Mountain, PA).
- Last spring frost
- April 26
- First fall frost
- October 17
- Growing season
- 172 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- November 8
- Last snow
- April 5
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
15 of 15 observed
NOAA normal
Frost risk by date in Ligonier
Half of springs at Laurel Mountain, PA see their last 32°F night by April 26; only one in ten is past it by April 13, and one in ten still has one after May 13. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 7 20%, and after May 13 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 50% of the 176 Pennsylvania stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 17 in half of years, as early as October 4 one year in ten, and holds off past October 29 one year in ten. A hard freeze of 28°F follows 12 days later, around October 29; in spring the one-in-ten date for 28°F is April 30, 13 days before the 32°F one. The freeze-free season lasts 172 days in a typical year, shorter than at 55% of the 176 Pennsylvania stations; it reaches 190 days one year in ten and falls short of 153 one year in ten. On average 126 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 11 days longer, to about May 7, and return around October 5. Severe cold of 16°F or below comes every winter, usually between December 5 and March 17.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 23 | Apr 27 | Apr 30 | May 3 | May 7 | May 10 | May 14 | May 18 | May 23 |
| 32°F | Apr 13 | Apr 18 | Apr 21 | Apr 23 | Apr 26 | Apr 30 | May 2 | May 7 | May 13 |
| 28°F | Apr 2 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 21 | Apr 24 | Apr 30 |
| 24°F | Mar 22 | Mar 30 | Apr 1 | Apr 4 | Apr 6 | Apr 8 | Apr 11 | Apr 14 | Apr 19 |
| 20°F | Mar 9 | Mar 16 | Mar 20 | Mar 24 | Mar 28 | Mar 31 | Apr 3 | Apr 5 | Apr 9 |
| 16°F | Feb 28 | Mar 5 | Mar 9 | Mar 14 | Mar 17 | Mar 20 | Mar 24 | Mar 27 | Mar 31 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 23 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 18 |
| 32°F | Oct 4 | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 22 | Oct 26 | Oct 29 |
| 28°F | Oct 15 | Oct 20 | Oct 23 | Oct 27 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 14 |
| 24°F | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 22 | Nov 29 |
| 20°F | Nov 7 | Nov 13 | Nov 16 | Nov 20 | Nov 23 | Nov 27 | Dec 1 | Dec 5 | Dec 12 |
| 16°F | Nov 16 | Nov 23 | Nov 28 | Dec 1 | Dec 5 | Dec 10 | Dec 15 | Dec 22 | Dec 29 |
Freeze probabilities 1991–2020 at Laurel Mountain, 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 15658 →Compare Ligonier with another place →
Weather by month in Ligonier
July is the warmest month at Laurel Mountain, PA, averaging 80°F by day and 61°F at night; January is the coldest at 36°F and 19°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 34% of years.
Warmth for growing adds up to 2,654 growing degree days a year (base 50°F), fewer than at 69% of the 176 Pennsylvania stations. 35% of them (927) have built up by the end of June, and July adds the most, 626. Precipitation totals 49.5 inches a year, most in June (5.0") and least in February (3.3"); May to September bring 46% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 36 | 19 | 4.1 | 100% | 28 | 2 |
| Feb | 39 | 20 | 3.3 | 100% | 25 | 4 |
| Mar | 48 | 27 | 4.3 | 100% | 21 | 31 |
| Apr | 61 | 38 | 4.6 | 99% | 7 | 119 |
| May | 69 | 48 | 4.5 | 34% | 1 | 281 |
| Jun | 76 | 57 | 5.0 | 0% | 0 | 491 |
| Jul | 80 | 61 | 4.7 | 0% | 0 | 626 |
| Aug | 78 | 59 | 4.0 | 0% | 0 | 580 |
| Sep | 72 | 52 | 4.4 | 4% | 0 | 355 |
| Oct | 62 | 41 | 3.6 | 93% | 4 | 133 |
| Nov | 50 | 33 | 3.4 | 100% | 14 | 27 |
| Dec | 41 | 26 | 3.6 | 100% | 25 | 6 |
Monthly normals 1991–2020 at Laurel Mountain, PA (2,760 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, Laurel Summit, PA, 7 miles southeast of Ligonier, has a last frost 10 days later (May 6), a first frost 5 days earlier (October 12), a season 13 days shorter.
When it snows in Ligonier, Pennsylvania
The first measurable snow (0.1 inch or more) in Ligonier usually arrives around November 8, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Laurel Mountain, PA, 3.9 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 21 days after the last snow.
Planting calendar for 15658
| When | What to do |
|---|---|
| February 15 – March 1 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 1 – March 15 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 29 – April 12 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 26 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 25 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 3 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 17 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 15658 is 4 miles from Laurel Mountain, PA, which stands at 2,760 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 15658 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°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.