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

Planting zone for 13673 — Philadelphia, NY

ZIP code 13673 (Philadelphia, Jefferson County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 14 and the first fall frost September 26.

Where ZIP 13673 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostMay 14
First frostSep 26
2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Philadelphia, NY…

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 Philadelphia, NY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 14median — 50% chance of a later frost
Safe for tender plantsMay 30only 10% chance of frost after
First fall frostSeptember 26median — 10% chance by Sep 12
Growing season134 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 8.

From the NOAA station Gouverneur 3 Nw, NY — 16 miles away, elevation 420 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 13673

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 2 – Apr 16
SpinachSow outdoors · Apr 2 – Apr 23
Broccoli, cabbageStart indoors · Mar 5 – Mar 19
Broccoli, cabbageTransplant · Apr 23 – May 7
Onion setsPlant outdoors · Apr 16 – Apr 30
PotatoesPlant outdoors · Apr 23 – May 7
LettuceSow outdoors · Apr 16 – Apr 30
Carrots, beetsSow outdoors · Apr 23 – May 7
TomatoesStart indoors · Mar 19 – Apr 2
TomatoesTransplant · May 21 – Jun 4
Peppers, eggplantStart indoors · Mar 5 – Mar 19
Peppers, eggplantTransplant · May 28 – Jun 11
BeansSow outdoors · May 21 – Jun 4
Sweet cornSow outdoors · May 21 – Jun 4
Cucumbers, squashSow outdoors · May 21 – Jun 4
Fall lettuce, spinachSow outdoors · Aug 1 – Aug 15
GarlicPlant cloves · Sep 12 – Oct 17
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 14) and first fall frost (Sep 26) 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 13673 came on Apr 15 — 3 days earlier than the 1991–2020 average (Apr 18).

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).

Native plants for zone 5a in New York

584 plants native to the lower 48 states, recorded in New York, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 68

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 116

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 201

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 179

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 7

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Philadelphia, NY.

Soil in Philadelphia, NY

The soil mapped at the center of ZIP 13673 is Madalin — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables
pH6.3slightly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter8%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Madalin silt loam, 0 to 3 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 13673; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Philadelphia, NY

Summer high79 °Faverage high, July
Winter low5 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights166nights a year at 32 °F or less
Growing degree days2,073base 50 °F — the season’s usable heat
Longest day15 h 31 mindaylight on June 21
Shortest day8 h 52 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation48.9 inper year, rain and melted snow

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 27 °F, low 5 °F 27°5° JanFebruary: average high 29 °F, low 6 °F 29°6° FebMarch: average high 39 °F, low 17 °F 39°17° MarApril: average high 53 °F, low 31 °F 53°31° AprMay: average high 66 °F, low 42 °F 66°42° MayJune: average high 75 °F, low 53 °F 75°53° JunJuly: average high 79 °F, low 57 °F 79°57° JulAugust: average high 78 °F, low 55 °F 78°55° AugSeptember: average high 71 °F, low 47 °F 71°47° SepOctober: average high 58 °F, low 36 °F 58°36° OctNovember: average high 45 °F, low 27 °F 45°27° NovDecember: average high 33 °F, low 15 °F 33°15° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 4.70 in precipitation 4.7 JanFebruary: 2.85 in precipitation 2.9 FebMarch: 4.17 in precipitation 4.2 MarApril: 3.57 in precipitation 3.6 AprMay: 3.48 in precipitation 3.5 MayJune: 4.75 in precipitation 4.8 JunJuly: 3.25 in precipitation 3.3 JulAugust: 4.03 in precipitation 4.0 AugSeptember: 4.43 in precipitation 4.4 SepOctober: 5.29 in precipitation 5.3 OctNovember: 3.87 in precipitation 3.9 NovDecember: 4.49 in precipitation 4.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Gouverneur 3 Nw, NY (16 mi away); precipitation: Theresa 4nw, NY (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

136915a
Theresa, NY · 4 mi
136084b
Antwerp, NY · 8 mi
136375a
Evans Mills, NY · 8 mi
136755a
Plessis, NY · 9 mi
136714b
Oxbow, NY · 9 mi
136025a
Fort Drum, NY · 9 mi
136285a
Deferiet, NY · 10 mi
136795a
Redwood, NY · 10 mi

New York planting zones →

Questions about 13673

What planting zone is ZIP code 13673?

ZIP code 13673 (Philadelphia, NY) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Philadelphia, NY?

The median last spring frost (32 °F) near 13673 is May 14; after May 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Gouverneur 3 Nw station.

When is the first frost in Philadelphia, NY?

The median first fall frost near 13673 is September 26, giving a median frost-free growing season of 134 days.

When should I plant tomatoes in 13673?

Start tomato seeds indoors around Mar 19 – Apr 2 and set transplants outside around May 21 – Jun 4, one to three weeks after the median last frost.

How much rain and snow does 13673 get?

About 48.9 inches of precipitation a year (NOAA 1991–2020 normals, Theresa 4nw station).

How hot do summers get in Philadelphia, NY?

The average high peaks at 79 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 13673 have?

The USDA soil survey maps Madalin at the center of ZIP 13673: silt loam, poorly drained, pH about 6.3 (slightly acidic).

Did spring come early in Philadelphia, NY in 2026?

Spring leaf-out near 13673 came on Apr 15 in 2026, 3 days earlier than the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Philadelphia, NY?

Long-day onions: the longest day near 13673 is 15 h 31 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 13673 change?

Yes. The 2012 USDA map put 13673 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.