USDA Hardiness Zone 7a
Frost Dates for 17353 — Orrtanna, Pennsylvania
NOAA 1991–2020 normals from Cashtown 1S, PA (710 ft), 2 miles east.
Updated
In Orrtanna, the last spring frost (32°F) is around April 28 in half of years and has passed by May 16 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 170 days (NOAA, Cashtown 1S, PA).
- Last spring frost
- April 28
- First fall frost
- October 17
- Growing season
- 170 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- December 10
- Last snow
- March 21
- Winters with snow
- 100%
- Snow per year
- 33"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in Orrtanna
Half of springs at Cashtown 1S, PA see their last 32°F night by April 28; 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 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 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 10 days later, around October 27; in spring the one-in-ten date for 28°F is May 1, 15 days before the 32°F one. The freeze-free season lasts 170 days in a typical year, shorter than at 60% of the 176 Pennsylvania stations; it reaches 188 days one year in ten and falls short of 150 one year in ten. On average 134 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 8 days longer, to about May 6, and return around October 6. Severe cold of 16°F or below comes every winter, usually between December 2 and March 12.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 24 | Apr 28 | May 1 | May 4 | May 6 | May 10 | May 13 | May 18 | May 22 |
| 32°F | Apr 15 | Apr 19 | Apr 23 | Apr 25 | Apr 28 | May 1 | May 4 | May 9 | May 16 |
| 28°F | Apr 2 | Apr 6 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 21 | Apr 25 | May 1 |
| 24°F | Mar 21 | Mar 26 | Mar 30 | Apr 1 | Apr 4 | Apr 7 | Apr 10 | Apr 14 | Apr 18 |
| 20°F | Mar 7 | Mar 13 | Mar 16 | Mar 20 | Mar 23 | Mar 26 | Mar 30 | Apr 1 | Apr 6 |
| 16°F | Feb 24 | Mar 1 | Mar 6 | Mar 9 | Mar 12 | Mar 15 | Mar 19 | Mar 22 | Mar 27 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 24 | Sep 29 | Oct 1 | Oct 4 | Oct 6 | Oct 8 | Oct 11 | Oct 14 | Oct 19 |
| 32°F | Oct 4 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 25 | Oct 29 |
| 28°F | Oct 13 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 8 |
| 24°F | Oct 24 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 20 |
| 20°F | Nov 3 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 21 | Nov 25 | Nov 30 | Dec 4 |
| 16°F | Nov 15 | Nov 20 | Nov 25 | Nov 29 | Dec 2 | Dec 6 | Dec 11 | Dec 17 | Dec 24 |
Freeze probabilities 1991–2020 at Cashtown 1S, 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 17353 →Compare Orrtanna with another place →
Compared with the next station
The nearest other station, S Mountain, PA, 7 miles west of Orrtanna and 810 feet higher, has a last frost 1 day earlier (April 27), a first frost 3 days later (October 20), a season 7 days longer.
When it snows in Orrtanna, Pennsylvania
The first measurable snow (0.1 inch or more) in Orrtanna usually arrives around December 10, and the last of the season around March 21. Those are the middle dates across the winters of 1991–2020 at S Mountain, PA, 6.8 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 38 days after the last snow.
Planting calendar for 17353
| When | What to do |
|---|---|
| February 17 – March 3 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 3 – March 17 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 31 – April 14 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 28 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 17353 is 2 miles from Cashtown 1S, PA, which stands at 710 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 17353 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°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.