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USDA Hardiness Zone 6a

Frost Dates for 15728 — Clymer, Pennsylvania

NOAA 1991–2020 normals from Indiana 3 SE, PA (1,102 ft), 9 miles southwest.

Updated

In Clymer, the last spring frost (32°F) is around May 8 in half of years and has passed by May 24 in nine years out of ten. The first fall frost comes around October 13, as early as October 1 one year in ten, leaving a typical freeze-free season of 157 days (NOAA, Indiana 3 SE, PA).

Last spring frost
May 8

50% probability

First fall frost
October 13

50% probability

Growing season
157 days

freeze-free, 50%

Hardiness zone
6a

-10 to -5°F (-23.3 to -20.6°C) coldest night

First snow
November 17

median, 1991–2020

Last snow
April 1

median, 1991–2020

Winters with snow
100%

30 of 30 observed

Snow per year
45.8"

NOAA normal

Frost risk by date in Clymer

Half of springs at Indiana 3 SE, PA see their last 32°F night by May 8; only one in ten is past it by April 23, and one in ten still has one after May 24. Planting tender crops after May 15 leaves a 30% risk of a frost on them, after May 19 20%, and after May 24 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 13 in half of years, as early as October 1 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 12 days later, around October 25; in spring the one-in-ten date for 28°F is May 14, 10 days before the 32°F one. The freeze-free season lasts 157 days in a typical year, shorter than at 80% of the 176 Pennsylvania stations; it reaches 178 days one year in ten and falls short of 136 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 20, and return around October 3. Severe cold of 16°F or below comes every winter, usually between November 27 and March 22.

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

Freeze probabilities 1991–2020 at Indiana 3 SE, 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 15728 →Compare Clymer with another place →

Weather by month in Clymer

July is the warmest month at Indiana 3 SE, PA, averaging 83°F by day and 59°F at night; January is the coldest at 36°F and 18°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 71% of years.

Warmth for growing adds up to 2,703 growing degree days a year (base 50°F), fewer than at 66% of the 176 Pennsylvania stations. 33% of them (904) have built up by the end of June, and July adds the most, 640. Precipitation totals 47.8 inches a year, most in July (5.1") and least in February (3.0"); May to September bring 47% of it.

Monthly normals 1991–2020 at Indiana 3 SE, PA
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan36183.6100%272
Feb39183.0100%242
Mar49253.9100%2219
Apr62354.0100%1092
May72464.371%2292
Jun79544.82%0497
Jul83595.10%0640
Aug81584.30%0601
Sep75514.210%<1393
Oct63403.594%5138
Nov51303.5100%1723
Dec41243.6100%254

Monthly normals 1991–2020 at Indiana 3 SE, PA (1,102 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, Ebensburg Sewage Plt, PA, 20 miles southeast of Clymer and 838 feet higher, has a last frost 9 days later (May 17), a first frost 11 days earlier (October 2), a season 21 days shorter.

Frost dates for 15931 (Ebensburg) →

When it snows in Clymer, Pennsylvania

The first measurable snow (0.1 inch or more) in Clymer usually arrives around November 17, and the last of the season around April 1. Those are the middle dates across the winters of 1991–2020 at Indiana 3 SE, PA, 8.6 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 37 days after the last snow.

Planting calendar for 15728

What to do and when, from the 50% frost dates for Clymer, Pennsylvania
WhenWhat to do
February 27 – March 13Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 13 – March 27Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
April 10 – April 24Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
May 8 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 21Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by September 29Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 13 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 15728 is 9 miles from Indiana 3 SE, PA, which stands at 1,102 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 15701 (Indiana). The 2023 USDA Plant Hardiness Zone Map lists ZIP 15728 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.

ZIP codes measured at the same station

Other zone 6a places in Pennsylvania