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

Planting zone for 05488 — Swanton, VT

ZIP code 05488 (Swanton, Franklin County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 1 and the first fall frost October 12.

Where ZIP 05488 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 1

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 Swanton, VT…

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 Swanton, VT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 1median — 50% chance of a later frost

Safe for tender plantsMay 16only 10% chance of frost after

First fall frostOctober 12median — 10% chance by Sep 28

Growing season161 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 21 and returns around October 23.

From the NOAA station St Albans Radio, VT — 5 miles away, elevation 381 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 05488

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 20 – Apr 3

SpinachSow outdoors · Mar 20 – Apr 10

Broccoli, cabbageStart indoors · Feb 20 – Mar 6

Broccoli, cabbageTransplant · Apr 10 – Apr 24

Onion setsPlant outdoors · Apr 3 – Apr 17

PotatoesPlant outdoors · Apr 10 – Apr 24

LettuceSow outdoors · Apr 3 – Apr 17

Carrots, beetsSow outdoors · Apr 10 – Apr 24

TomatoesStart indoors · Mar 6 – Mar 20

TomatoesTransplant · May 8 – May 22

Peppers, eggplantStart indoors · Feb 20 – Mar 6

Peppers, eggplantTransplant · May 15 – May 29

BeansSow outdoors · May 8 – May 22

Sweet cornSow outdoors · May 8 – May 22

Cucumbers, squashSow outdoors · May 8 – May 22

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 (May 1) 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 05488 came on Apr 16 — 3 days earlier than the 1991–2020 average (Apr 19).

average
Apr 192026
Apr 16

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 Swanton, VT

The soil mapped at the center of ZIP 05488 is Terric Medisaprists — muck, very poorly drained.

TextureMucktop layer

pH5.4strongly acidic; most vegetables like 6.0–7.0

DrainageVery poorly drainedconsider raised beds

Organic matter80%high

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Terric Medisaprists.

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 05488; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Swanton, VT

Summer high79 °Faverage high, July

Winter low8 °Faverage low, January

Hot days3days a year at 90 °F or more

Freezing nights148nights a year at 32 °F or less

Growing degree days2,304base 50 °F — the season’s usable heat

Longest day15 h 36 mindaylight on June 21

Shortest day8 h 46 mindaylight on December 21

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

Precipitation38.3 inper year, rain and melted snow

Snowfall80 inper year; 86 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: St Albans Radio, VT (5 mi away); precipitation: St Albans Radio, VT (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

054605a

Highgate Springs, VT · 4 mi

054595a

Highgate Center, VT · 7 mi

054745a

North Hero, VT · 7 mi

054405a

Alburgh, VT · 8 mi

054815a

Saint Albans Bay, VT · 8 mi

054835a

Sheldon, VT · 8 mi

054795a

Saint Albans, VT · 8 mi

054855a

Sheldon Springs, VT · 8 mi

Vermont planting zones →

Questions about 05488

What planting zone is ZIP code 05488?

ZIP code 05488 (Swanton, VT) 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 Swanton, VT?

The median last spring frost (32 °F) near 05488 is May 1; after May 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, St Albans Radio station.

When is the first frost in Swanton, VT?

The median first fall frost near 05488 is October 12, giving a median frost-free growing season of 161 days.

When should I plant tomatoes in 05488?

Start tomato seeds indoors around Mar 6 – Mar 20 and set transplants outside around May 8 – May 22, one to three weeks after the median last frost.

How much rain and snow does 05488 get?

About 38.3 inches of precipitation a year and 80 inches of snowfall (NOAA 1991–2020 normals, St Albans Radio station).

How hot do summers get in Swanton, VT?

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 05488 have?

The USDA soil survey maps Terric Medisaprists at the center of ZIP 05488: muck, very poorly drained, pH about 5.4 (strongly acidic).

Did spring come early in Swanton, VT in 2026?

Spring leaf-out near 05488 came on Apr 16 in 2026, 3 days earlier than the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Swanton, VT?

Long-day onions: the longest day near 05488 is 15 h 36 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 05488 change?

Yes. The 2012 USDA map put 05488 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.