USDA Hardiness Zone 6a
Frost Dates for 16242 — New Bethlehem, Pennsylvania
NOAA 1991–2020 normals from Putneyville 2 SE Dam, PA (1,280 ft), 7 miles southeast.
Updated
In New Bethlehem, the last spring frost (32°F) is around May 10 in half of years and has passed by May 28 in nine years out of ten. The first fall frost comes around October 12, as early as September 30 one year in ten, leaving a typical freeze-free season of 155 days (NOAA, Putneyville 2 SE Dam, PA).
- Last spring frost
- May 10
- First fall frost
- October 12
- Growing season
- 155 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
- December 5
- Last snow
- March 22
- Winters with snow
- 96%
- Snow per year
- 34.5"
median, 1991–2020
median, 1991–2020
25 of 26 observed
NOAA normal
Frost risk by date in New Bethlehem
Half of springs at Putneyville 2 SE Dam, PA see their last 32°F night by May 10; only one in ten is past it by April 24, and one in ten still has one after May 28. Planting tender crops after May 19 leaves a 30% risk of a frost on them, after May 23 20%, and after May 28 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 12 in half of years, as early as September 30 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 14 days later, around October 26; in spring the one-in-ten date for 28°F is May 19, 9 days before the 32°F one. The freeze-free season lasts 155 days in a typical year, shorter than at 82% of the 176 Pennsylvania stations; it reaches 177 days one year in ten and falls short of 131 one year in ten. On average 152 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 21, and return around October 1. Severe cold of 16°F or below comes every winter, usually between December 1 and March 23.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 2 | May 8 | May 13 | May 18 | May 21 | May 25 | May 28 | Jun 1 | Jun 4 |
| 32°F | Apr 24 | Apr 29 | May 2 | May 7 | May 10 | May 14 | May 19 | May 23 | May 28 |
| 28°F | Apr 15 | Apr 19 | Apr 22 | Apr 26 | Apr 28 | May 2 | May 7 | May 12 | May 19 |
| 24°F | Apr 1 | Apr 6 | Apr 9 | Apr 13 | Apr 16 | Apr 19 | Apr 23 | Apr 30 | May 7 |
| 20°F | Mar 19 | Mar 25 | Mar 29 | Apr 1 | Apr 3 | Apr 6 | Apr 9 | Apr 14 | Apr 18 |
| 16°F | Mar 6 | Mar 12 | Mar 16 | Mar 19 | Mar 23 | Mar 27 | Mar 30 | Apr 1 | Apr 6 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 18 | Sep 23 | Sep 27 | Sep 30 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 14 |
| 32°F | Sep 30 | Oct 3 | Oct 6 | Oct 8 | Oct 12 | Oct 15 | Oct 19 | Oct 22 | Oct 27 |
| 28°F | Oct 10 | Oct 16 | Oct 19 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 8 |
| 24°F | Oct 22 | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 16 | Nov 20 |
| 20°F | Nov 4 | Nov 8 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 26 | Dec 1 | Dec 5 |
| 16°F | Nov 12 | Nov 18 | Nov 24 | Nov 28 | Dec 1 | Dec 3 | Dec 8 | Dec 13 | Dec 21 |
Freeze probabilities 1991–2020 at Putneyville 2 SE Dam, 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 16242 →Compare New Bethlehem with another place →
Weather by month in New Bethlehem
July is the warmest month at Putneyville 2 SE Dam, PA, averaging 82°F by day and 58°F at night; January is the coldest at 35°F and 17°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 72% of years.
Warmth for growing adds up to 2,597 growing degree days a year (base 50°F), fewer than at 72% of the 176 Pennsylvania stations. 34% of them (874) have built up by the end of June, and July adds the most, 625. Precipitation totals 45.9 inches a year, most in June (4.8") and least in February (2.9"); May to September bring 47% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 35 | 17 | 3.4 | 100% | 28 | 2 |
| Feb | 38 | 18 | 2.9 | 100% | 26 | 2 |
| Mar | 47 | 24 | 3.6 | 100% | 25 | 18 |
| Apr | 61 | 35 | 4.1 | 100% | 14 | 88 |
| May | 71 | 45 | 4.1 | 72% | 3 | 273 |
| Jun | 78 | 54 | 4.8 | 5% | <1 | 490 |
| Jul | 82 | 58 | 4.7 | 0% | 0 | 625 |
| Aug | 81 | 57 | 3.8 | 0% | 0 | 589 |
| Sep | 74 | 50 | 4.1 | 10% | 1 | 368 |
| Oct | 62 | 39 | 3.3 | 94% | 9 | 119 |
| Nov | 50 | 30 | 3.6 | 100% | 20 | 19 |
| Dec | 39 | 23 | 3.5 | 100% | 27 | 4 |
Monthly normals 1991–2020 at Putneyville 2 SE Dam, PA (1,280 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, Clarion 3 SW, PA, 14 miles north of New Bethlehem and 240 feet lower, has a last frost 1 day earlier (May 9), a first frost 1 day earlier (October 11), a season 1 day shorter.
When it snows in New Bethlehem, Pennsylvania
The first measurable snow (0.1 inch or more) in New Bethlehem usually arrives around December 5, and the last of the season around March 22. Those are the middle dates across the winters of 1991–2020 at Putneyville 2 SE Dam, PA, 6.6 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 49 days after the last snow.
Planting calendar for 16242
| When | What to do |
|---|---|
| March 1 – March 15 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 15 – March 29 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 12 – April 26 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 10 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 20 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 28 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 12 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 16242 is 7 miles from Putneyville 2 SE Dam, PA, which stands at 1,280 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 16242 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.