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USDA Hardiness Zone 6a

Frost Dates for 15445 — Hopwood, Pennsylvania

NOAA 1991–2020 normals from Uniontown 1 NE, PA (956 ft), 3 miles northwest.

Updated

In Hopwood, the last spring frost (32°F) is around April 30 in half of years and has passed by May 18 in nine years out of ten. The first fall frost comes around October 18, as early as October 5 one year in ten, leaving a typical freeze-free season of 171 days (NOAA, Uniontown 1 NE, PA).

Last spring frost
April 30

50% probability

First fall frost
October 18

50% probability

Growing season
171 days

freeze-free, 50%

Hardiness zone
6a

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

First snow
November 30

median, 1991–2020

Last snow
March 20

median, 1991–2020

Winters with snow
100%

28 of 28 observed

Snow per year
28.1"

NOAA normal

Frost risk by date in Hopwood

Half of springs at Uniontown 1 NE, PA see their last 32°F night by April 30; only one in ten is past it by April 15, and one in ten still has one after May 18. Planting tender crops after May 7 leaves a 30% risk of a frost on them, after May 12 20%, and after May 18 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 18 in half of years, as early as October 5 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 10 days later, around October 28; in spring the one-in-ten date for 28°F is May 6, 12 days before the 32°F one. The freeze-free season lasts 171 days in a typical year, shorter than at 57% of the 176 Pennsylvania stations; it reaches 191 days one year in ten and falls short of 149 one year in ten. On average 129 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 10, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 3 and March 11.

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

Freeze probabilities 1991–2020 at Uniontown 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 15445 →Compare Hopwood with another place →

Weather by month in Hopwood

July is the warmest month at Uniontown 1 NE, PA, averaging 84°F by day and 62°F at night; January is the coldest at 40°F and 21°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 48% of years.

Warmth for growing adds up to 3,185 growing degree days a year (base 50°F), more than at 68% of the 176 Pennsylvania stations. 35% of them (1,112) have built up by the end of June, and July adds the most, 716. Precipitation totals 44.5 inches a year, most in June (4.8") and least in February (2.8"); May to September bring 48% of it.

Monthly normals 1991–2020 at Uniontown 1 NE, PA
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan40213.3100%268
Feb43232.8100%249
Mar51293.7100%2136
Apr64383.898%10142
May73484.448%1347
Jun81574.80%0570
Jul84624.80%0716
Aug83603.60%0673
Sep78533.63%<1460
Oct66413.292%7174
Nov54323.2100%1738
Dec44263.3100%2413

Monthly normals 1991–2020 at Uniontown 1 NE, PA (956 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, Chalk Hill 2 ENE, PA, 6 miles east of Hopwood and 1,024 feet higher, has a last frost 19 days later (May 19), a first frost 17 days earlier (October 1), a season 36 days shorter.

Frost dates for 15437 (Farmington) →

When it snows in Hopwood, Pennsylvania

The first measurable snow (0.1 inch or more) in Hopwood usually arrives around November 30, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Uniontown 1 NE, PA, 3 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 41 days after the last snow.

Planting calendar for 15445

What to do and when, from the 50% frost dates for Hopwood, Pennsylvania
WhenWhat to do
February 19 – March 5Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 5 – March 19Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
April 2 – April 16Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 30 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 15445 is 3 miles from Uniontown 1 NE, PA, which stands at 956 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 15401 (Uniontown). The 2023 USDA Plant Hardiness Zone Map lists ZIP 15445 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