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

Planting zone for 12910 — Altona, NY

ZIP code 12910 (Altona, Clinton County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 30 and the first fall frost October 12.

Where ZIP 12910 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 frostApr 30
First frostOct 12
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 Altona, 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 Altona, NY

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 14only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Sep 29
Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 25.

From the NOAA station Chazy, NY — 11 miles away, elevation 157 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 12910

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 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 12) 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 12910 came on Apr 19 — 3 days earlier than the 1991–2020 average (Apr 22).

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 Altona, NY.

Soil in Altona, NY

The soil mapped at the center of ZIP 12910 is Ricker — peat, well drained.

TexturePeattop layer
DrainageWell drainednatural drainage class
Organic matter90%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Rock outcrop-Ricker complex, gently sloping.

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 12910; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Altona, NY

Summer high82 °Faverage high, July
Winter low10 °Faverage low, January
Hot days4days a year at 90 °F or more
Freezing nights152nights a year at 32 °F or less
Growing degree days2,648base 50 °F — the season’s usable heat
Longest day15 h 36 mindaylight on June 21
Shortest day8 h 47 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation43.4 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 28 °F, low 10 °F 28°10° JanFebruary: average high 31 °F, low 12 °F 31°12° FebMarch: average high 41 °F, low 23 °F 41°23° MarApril: average high 56 °F, low 36 °F 56°36° AprMay: average high 69 °F, low 47 °F 69°47° MayJune: average high 78 °F, low 57 °F 78°57° JunJuly: average high 82 °F, low 63 °F 82°63° JulAugust: average high 80 °F, low 60 °F 80°60° AugSeptember: average high 72 °F, low 52 °F 72°52° SepOctober: average high 59 °F, low 41 °F 59°41° OctNovember: average high 46 °F, low 31 °F 46°31° NovDecember: average high 34 °F, low 20 °F 34°20° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.92 in precipitation 2.9 JanFebruary: 2.27 in precipitation 2.3 FebMarch: 2.80 in precipitation 2.8 MarApril: 3.83 in precipitation 3.8 AprMay: 3.95 in precipitation 4.0 MayJune: 4.90 in precipitation 4.9 JunJuly: 4.24 in precipitation 4.2 JulAugust: 4.08 in precipitation 4.1 AugSeptember: 3.85 in precipitation 3.9 SepOctober: 4.67 in precipitation 4.7 OctNovember: 2.91 in precipitation 2.9 NovDecember: 2.94 in precipitation 2.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Chazy, NY (11 mi away); precipitation: Dannemora, NY (11 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.

129925a
West Chazy, NY · 5 mi
129585a
Mooers, NY · 7 mi
129594b
Mooers Forks, NY · 9 mi
129215a
Chazy, NY · 9 mi
129355a
Ellenburg Depot, NY · 9 mi
129625a
Morrisonville, NY · 10 mi
129195a
Champlain, NY · 11 mi
129295a
Dannemora, NY · 11 mi

New York planting zones →

Questions about 12910

What planting zone is ZIP code 12910?

ZIP code 12910 (Altona, 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 Altona, NY?

The median last spring frost (32 °F) near 12910 is April 30; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Chazy station.

When is the first frost in Altona, NY?

The median first fall frost near 12910 is October 12, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 12910?

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 12910 get?

About 43.4 inches of precipitation a year (NOAA 1991–2020 normals, Dannemora station).

How hot do summers get in Altona, NY?

The average high peaks at 82 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 12910 have?

The USDA soil survey maps Ricker at the center of ZIP 12910: peat, well drained.

Did spring come early in Altona, NY in 2026?

Spring leaf-out near 12910 came on Apr 19 in 2026, 3 days earlier than the 1991–2020 average (Apr 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Altona, NY?

Long-day onions: the longest day near 12910 is 15 h 36 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 12910 change?

Yes. The 2012 USDA map put 12910 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.