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USDA Hardiness Zone 7a

Frost Dates for 17068 — New Bloomfield, Pennsylvania

NOAA 1991–2020 normals from Carlisle Wtp, PA (430 ft), 13 miles south.

Updated

In New Bloomfield, the last spring frost (32°F) is around April 23 in half of years and has passed by May 9 in nine years out of ten. The first fall frost comes around October 18, as early as October 4 one year in ten, leaving a typical freeze-free season of 177 days (NOAA, Carlisle Wtp, PA).

Last spring frost
April 23

50% probability

First fall frost
October 18

50% probability

Growing season
177 days

freeze-free, 50%

Hardiness zone
7a

0 to 5°F (-17.8 to -15.0°C) coldest night

First snow
January 9

median, 1991–2020

Last snow
March 11

median, 1991–2020

Winters with snow
100%

17 of 17 observed

Snow per year
—

NOAA normal

Frost risk by date in New Bloomfield

Half of springs at Carlisle Wtp, PA see their last 32°F night by April 23; only one in ten is past it by April 9, and one in ten still has one after May 9. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 3 20%, and after May 9 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 51% 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 4 one year in ten, and holds off past November 2 one year in ten. A hard freeze of 28°F follows 14 days later, around November 1; in spring the one-in-ten date for 28°F is April 24, 15 days before the 32°F one. The freeze-free season lasts 177 days in a typical year, longer than at 56% of the 176 Pennsylvania stations; it reaches 198 days one year in ten and falls short of 155 one year in ten. On average 127 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 3, and return around October 6. Severe cold of 16°F or below comes every winter, usually between December 9 and March 6.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FApr 20Apr 25Apr 28Apr 30May 3May 6May 10May 14May 19
32°FApr 9Apr 14Apr 17Apr 20Apr 23Apr 26Apr 30May 3May 9
28°FMar 28Apr 1Apr 4Apr 7Apr 10Apr 13Apr 15Apr 18Apr 24
24°FMar 13Mar 18Mar 22Mar 26Mar 29Mar 31Apr 2Apr 5Apr 10
20°FFeb 28Mar 6Mar 9Mar 13Mar 16Mar 19Mar 23Mar 26Mar 31
16°FFeb 17Feb 24Feb 28Mar 2Mar 6Mar 9Mar 12Mar 16Mar 22
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FSep 25Sep 30Oct 2Oct 4Oct 6Oct 9Oct 12Oct 16Oct 21
32°FOct 4Oct 8Oct 11Oct 15Oct 18Oct 21Oct 24Oct 29Nov 2
28°FOct 14Oct 20Oct 24Oct 28Nov 1Nov 3Nov 5Nov 9Nov 14
24°FOct 28Nov 1Nov 5Nov 8Nov 12Nov 15Nov 18Nov 22Nov 29
20°FNov 9Nov 14Nov 18Nov 22Nov 27Nov 30Dec 3Dec 6Dec 15
16°FNov 21Nov 29Dec 2Dec 5Dec 9Dec 14Dec 19Dec 24Dec 30

Freeze probabilities 1991–2020 at Carlisle Wtp, 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 17068 →Compare New Bloomfield with another place →

Weather by month in New Bloomfield

July is the warmest month at Carlisle Wtp, PA, averaging 86°F by day and 63°F at night; January is the coldest at 38°F and 21°F. A freezing night is all but certain in every month from November 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 26% of years.

Warmth for growing adds up to 3,156 growing degree days a year (base 50°F), more than at 65% of the 176 Pennsylvania stations. 34% of them (1,071) have built up by the end of June, and July adds the most, 744. Precipitation totals 48.2 inches a year, most in July (5.5") and least in February (2.6"); May to September bring 49% of it.

Monthly normals 1991–2020 at Carlisle Wtp, PA
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan38213.1100%281
Feb41222.6100%253
Mar50294.1100%2122
Apr63393.898%7113
May73494.726%<1338
Jun81594.40%0594
Jul86635.50%0744
Aug84614.00%0691
Sep77535.02%0460
Oct66424.385%4165
Nov54323.1100%1724
Dec42253.6100%252

Monthly normals 1991–2020 at Carlisle Wtp, PA (430 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, Bloserville 1 N, PA, 14 miles southwest of New Bloomfield and 270 feet higher, has a last frost 5 days earlier (April 18), a first frost 8 days later (October 26), a season 14 days longer.

Frost dates for 17241 (Newville) →

When it snows in New Bloomfield, Pennsylvania

The first measurable snow (0.1 inch or more) in New Bloomfield usually arrives around January 9, and the last of the season around March 11. Those are the middle dates across the winters of 1991–2020 at Bloserville 1 N, PA, 14 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 43 days after the last snow.

Planting calendar for 17068

What to do and when, from the 50% frost dates for New Bloomfield, Pennsylvania
WhenWhat to do
February 12 – February 26Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 26 – March 12Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 26 – April 9Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 23 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 26Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 4Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 18 onwardPlant 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 17068 is 13 miles from Carlisle Wtp, PA, which stands at 430 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 17013 (Carlisle). The 2023 USDA Plant Hardiness Zone Map lists ZIP 17068 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.

ZIP codes measured at the same station

Other zone 7a places in Pennsylvania