Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 17751 — Mill Hall, PA

ZIP code 17751 (Mill Hall, Clinton County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 30 and the first fall frost October 20.

Where ZIP 17751 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostApr 30

First frostOct 20

2012 zone6a

Was 6a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mill Hall, PA…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Mill Hall, PA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 30median — 50% chance of a later frost

Safe for tender plantsMay 15only 10% chance of frost after

First fall frostOctober 20median — 10% chance by Oct 5

Growing season173 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 16 and returns around November 1.

From the NOAA station Lock Haven Sewage Plt, PA — 4 miles away, elevation 568 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 17751

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 19 – Apr 2

SpinachSow outdoors · Mar 19 – Apr 9

Broccoli, cabbageStart indoors · Feb 19 – Mar 5

Broccoli, cabbageTransplant · Apr 9 – Apr 23

Onion setsPlant outdoors · Apr 2 – Apr 16

PotatoesPlant outdoors · Apr 9 – Apr 23

LettuceSow outdoors · Apr 2 – Apr 16

Carrots, beetsSow outdoors · Apr 9 – Apr 23

TomatoesStart indoors · Mar 5 – Mar 19

TomatoesTransplant · May 7 – May 21

Peppers, eggplantStart indoors · Feb 19 – Mar 5

Peppers, eggplantTransplant · May 14 – May 28

BeansSow outdoors · May 7 – May 21

Sweet cornSow outdoors · May 7 – May 21

Cucumbers, squashSow outdoors · May 7 – May 21

Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8

GarlicPlant cloves · Oct 6 – Nov 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 20) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 17751 came on Mar 31 — 8 days earlier than the 1991–2020 average (Apr 8).

average
Apr 82026
Mar 31

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Soil in Mill Hall, PA

The soil mapped at the center of ZIP 17751 is Berks — channery silt loam, well drained.

TextureChannery silt loama good balance for most vegetables

pH5.8moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Berks-Weikert complex, 25 to 60 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 17751; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mill Hall, PA

Summer high85 °Faverage high, July

Winter low18 °Faverage low, January

Hot days18days a year at 90 °F or more

Freezing nights138nights a year at 32 °F or less

Growing degree days2,948base 50 °F — the season’s usable heat

Longest day15 h 08 mindaylight on June 21

Shortest day9 h 12 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation41.7 inper year, rain and melted snow

Snowfall30 inper year; 37 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Lock Haven Sewage Plt, PA (4 mi away); precipitation: Lock Haven Sewage Plt, PA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

177266b

Castanea, PA · 5 mi

177506b

Mackeyville, PA · 5 mi

Mc Elhattan, PA · 10 mi

168226b

Beech Creek, PA · 10 mi

168416b

Howard, PA · 11 mi

Pennsylvania planting zones →

Questions about 17751

What planting zone is ZIP code 17751?

ZIP code 17751 (Mill Hall, PA) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Mill Hall, PA?

The median last spring frost (32 °F) near 17751 is April 30; after May 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lock Haven Sewage Plt station.

When is the first frost in Mill Hall, PA?

The median first fall frost near 17751 is October 20, giving a median frost-free growing season of 173 days.

When should I plant tomatoes in 17751?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 17751 get?

About 41.7 inches of precipitation a year and 30 inches of snowfall (NOAA 1991–2020 normals, Lock Haven Sewage Plt station).

How hot do summers get in Mill Hall, PA?

The average high peaks at 85 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 17751 have?

The USDA soil survey maps Berks at the center of ZIP 17751: channery silt loam, well drained, pH about 5.8 (moderately acidic).

Did spring come early in Mill Hall, PA in 2026?

Spring leaf-out near 17751 came on Mar 31 in 2026, 8 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mill Hall, PA?

Long-day onions: the longest day near 17751 is 15 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 17751 change?

Yes. The 2012 USDA map put 17751 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.