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

Planting zone for 16638 — Entriken, PA

ZIP code 16638 (Entriken, Huntingdon County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 23 and the first fall frost October 21.

Where ZIP 16638 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 23

First frostOct 21

2012 zone6b

Same zone as on the 2012 map. 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 Entriken, 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 Entriken, PA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 23median — 50% chance of a later frost

Safe for tender plantsMay 11only 10% chance of frost after

First fall frostOctober 21median — 10% chance by Oct 5

Growing season177 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 11 and returns around November 1.

From the NOAA station Altoona Blair Co. Airport, PA — 7 miles away, elevation 1,480 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 16638

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 12 – Mar 26

SpinachSow outdoors · Mar 12 – Apr 2

Broccoli, cabbageStart indoors · Feb 12 – Feb 26

Broccoli, cabbageTransplant · Apr 2 – Apr 16

Onion setsPlant outdoors · Mar 26 – Apr 9

PotatoesPlant outdoors · Apr 2 – Apr 16

LettuceSow outdoors · Mar 26 – Apr 9

Carrots, beetsSow outdoors · Apr 2 – Apr 16

TomatoesStart indoors · Feb 26 – Mar 12

TomatoesTransplant · Apr 30 – May 14

Peppers, eggplantStart indoors · Feb 12 – Feb 26

Peppers, eggplantTransplant · May 7 – May 21

BeansSow outdoors · Apr 30 – May 14

Sweet cornSow outdoors · Apr 30 – May 14

Cucumbers, squashSow outdoors · Apr 30 – May 14

Fall lettuce, spinachSow outdoors · Aug 26 – Sep 9

GarlicPlant cloves · Oct 7 – Nov 11

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 23) and first fall frost (Oct 21) 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 16638 came on Mar 20 — 13 days earlier than the 1991–2020 average (Apr 2).

average
Apr 22026
Mar 20

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 Entriken, PA

The soil mapped at the center of ZIP 16638 is Vanderlip — loamy sand, well drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.25%low — add compost

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Vanderlip loamy sand, 5 to 25 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 16638; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Entriken, PA

Summer high83 °Faverage high, July

Winter low21 °Faverage low, January

Hot days8days a year at 90 °F or more

Freezing nights118nights a year at 32 °F or less

Growing degree days2,977base 50 °F — the season’s usable heat

Longest day15 h 03 mindaylight on June 21

Shortest day9 h 17 mindaylight on December 21

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

Precipitation36.6 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Altoona Blair Co. Airport, PA (7 mi away); precipitation: Altoona Blair Co. Airport, PA (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

166576b

James Creek, PA · 2 mi

166477a

Hesston, PA · 5 mi

166626b

Martinsburg, PA · 6 mi

Williamsburg, PA · 9 mi

Pennsylvania planting zones →

Questions about 16638

What planting zone is ZIP code 16638?

ZIP code 16638 (Entriken, 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 Entriken, PA?

The median last spring frost (32 °F) near 16638 is April 23; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Altoona Blair Co. Airport station.

When is the first frost in Entriken, PA?

The median first fall frost near 16638 is October 21, giving a median frost-free growing season of 177 days.

When should I plant tomatoes in 16638?

Start tomato seeds indoors around Feb 26 – Mar 12 and set transplants outside around Apr 30 – May 14, one to three weeks after the median last frost.

How much rain and snow does 16638 get?

About 36.6 inches of precipitation a year (NOAA 1991–2020 normals, Altoona Blair Co. Airport station).

How hot do summers get in Entriken, PA?

The average high peaks at 83 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 16638 have?

The USDA soil survey maps Vanderlip at the center of ZIP 16638: loamy sand, well drained, pH about 5.3 (strongly acidic).

Did spring come early in Entriken, PA in 2026?

Spring leaf-out near 16638 came on Mar 20 in 2026, 13 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Entriken, PA?

Long-day onions: the longest day near 16638 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).