USDA Hardiness Zone 6b
Frost Dates for 16117 — Ellwood City, Pennsylvania
NOAA 1991–2020 normals from Beaver Falls 1 NE, PA (760 ft), 7 miles south.
Updated
In Ellwood City, the last spring frost (32°F) is around April 27 in half of years and has passed by May 16 in nine years out of ten. The first fall frost comes around October 25, as early as October 7 one year in ten, leaving a typical freeze-free season of 178 days (NOAA, Beaver Falls 1 NE, PA).
- Last spring frost
- April 27
- First fall frost
- October 25
- Growing season
- 178 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
- December 4
- Last snow
- March 18
- Winters with snow
- 96%
- Snow per year
- 27.5"
median, 1991–2020
median, 1991–2020
27 of 28 observed
NOAA normal
Frost risk by date in Ellwood City
Half of springs at Beaver Falls 1 NE, PA see their last 32°F night by April 27; only one in ten is past it by April 15, and one in ten still has one after May 16. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 9 20%, and after May 16 10%. The 19 days between the even-odds date and the one-in-ten date is wider than at 90% of the 176 Pennsylvania stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 25 in half of years, as early as October 7 one year in ten, and holds off past November 7 one year in ten. A hard freeze of 28°F follows 11 days later, around November 5; in spring the one-in-ten date for 28°F is May 4, 12 days before the 32°F one. The freeze-free season lasts 178 days in a typical year, longer than at 61% of the 176 Pennsylvania stations; it reaches 198 days one year in ten and falls short of 155 one year in ten. On average 131 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 12 days longer, to about May 9, and return around October 12. Severe cold of 16°F or below comes every winter, usually between December 6 and March 13.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 23 | Apr 27 | May 1 | May 6 | May 9 | May 13 | May 17 | May 21 | May 26 |
| 32°F | Apr 15 | Apr 19 | Apr 22 | Apr 24 | Apr 27 | Apr 30 | May 4 | May 9 | May 16 |
| 28°F | Apr 1 | Apr 6 | Apr 10 | Apr 14 | Apr 17 | Apr 19 | Apr 22 | Apr 26 | May 4 |
| 24°F | Mar 18 | Mar 23 | Mar 28 | Mar 31 | Apr 2 | Apr 5 | Apr 9 | Apr 13 | Apr 17 |
| 20°F | Mar 6 | Mar 12 | Mar 17 | Mar 20 | Mar 23 | Mar 27 | Mar 30 | Apr 2 | Apr 8 |
| 16°F | Feb 25 | Mar 2 | Mar 6 | Mar 9 | Mar 13 | Mar 16 | Mar 19 | Mar 23 | Mar 28 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 28 | Oct 2 | Oct 5 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 28 |
| 32°F | Oct 7 | Oct 14 | Oct 18 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 7 |
| 28°F | Oct 23 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 18 |
| 24°F | Nov 4 | Nov 7 | Nov 10 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 25 | Dec 1 |
| 20°F | Nov 8 | Nov 14 | Nov 18 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 6 | Dec 14 |
| 16°F | Nov 17 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 11 | Dec 15 | Dec 21 | Dec 29 |
Freeze probabilities 1991–2020 at Beaver Falls 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 16117 →Compare Ellwood City with another place →
Compared with the next station
The nearest other station, New Castle 1 N, PA, 12 miles north of Ellwood City, has a last frost 3 days later (April 30), a first frost 2 days earlier (October 23), a season 3 days shorter.
When it snows in Ellwood City, Pennsylvania
The first measurable snow (0.1 inch or more) in Ellwood City usually arrives around December 4, and the last of the season around March 18. Those are the middle dates across the winters of 1991–2020 at New Castle 1 N, PA, 11.9 miles away: half of years saw snow earlier, half later. Snow fell in 96% of those winters. The last 32°F night of spring typically comes 40 days after the last snow.
Planting calendar for 16117
| When | What to do |
|---|---|
| February 16 – March 2 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 2 – March 16 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 30 – April 13 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 27 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 2 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 11 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 25 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 16117 is 7 miles from Beaver Falls 1 NE, PA, which stands at 760 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 12 other ZIP codes share the station; its figures are presented in full for 16066 (Cranberry Township). The 2023 USDA Plant Hardiness Zone Map lists ZIP 16117 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.