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

Planting zone for 05403 — South Burlington, VT

ZIP code 05403 (South Burlington, Chittenden County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 29 and the first fall frost October 15.

Where ZIP 05403 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 29

First frostOct 15

2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for South Burlington, 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 South Burlington, VT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 29median — 50% chance of a later frost

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

First fall frostOctober 15median — 10% chance by Oct 2

Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 28.

From the NOAA station Burlington Intl Airport, VT — 2 miles away, elevation 331 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 05403

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 18 – Apr 1

SpinachSow outdoors · Mar 18 – Apr 8

Broccoli, cabbageStart indoors · Feb 18 – Mar 4

Broccoli, cabbageTransplant · Apr 8 – Apr 22

Onion setsPlant outdoors · Apr 1 – Apr 15

PotatoesPlant outdoors · Apr 8 – Apr 22

LettuceSow outdoors · Apr 1 – Apr 15

Carrots, beetsSow outdoors · Apr 8 – Apr 22

TomatoesStart indoors · Mar 4 – Mar 18

TomatoesTransplant · May 6 – May 20

Peppers, eggplantStart indoors · Feb 18 – Mar 4

Peppers, eggplantTransplant · May 13 – May 27

BeansSow outdoors · May 6 – May 20

Sweet cornSow outdoors · May 6 – May 20

Cucumbers, squashSow outdoors · May 6 – May 20

Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3

GarlicPlant cloves · Oct 1 – Nov 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 15) 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 05403 came on Apr 16 — about the same time as the 1991–2020 average (Apr 18).

average
Apr 182026
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 South Burlington, VT

The soil mapped at the center of ZIP 05403 is Vergennes — clay, moderately well drained.

TextureClayholds water and nutrients; slow to drain and warm up

pH5.9moderately acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter4%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Vergennes clay, 2 to 6 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 05403; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in South Burlington, VT

Summer high82 °Faverage high, July

Winter low13 °Faverage low, January

Hot days8days a year at 90 °F or more

Freezing nights145nights a year at 32 °F or less

Growing degree days2,724base 50 °F — the season’s usable heat

Longest day15 h 33 mindaylight on June 21

Shortest day8 h 50 mindaylight on December 21

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

Precipitation37.5 inper year, rain and melted snow

Snowfall88 inper year; 89 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: Burlington Intl Airport, VT (2 mi away); precipitation: Burlington Intl Airport, VT (2 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.

054055a

Burlington, VT · 2 mi

054015b

Burlington, VT · 3 mi

054395a

Colchester, VT · 4 mi

Burlington, VT · 4 mi

054065a

Burlington, VT · 4 mi

054075a

South Burlington, VT · 4 mi

All 2 ZIP codes in South Burlington → · Vermont planting zones →

Questions about 05403

What planting zone is ZIP code 05403?

ZIP code 05403 (South Burlington, 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 South Burlington, VT?

The median last spring frost (32 °F) near 05403 is April 29; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Burlington Intl Airport station.

When is the first frost in South Burlington, VT?

The median first fall frost near 05403 is October 15, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 05403?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 05403 get?

About 37.5 inches of precipitation a year and 88 inches of snowfall (NOAA 1991–2020 normals, Burlington Intl Airport station).

How hot do summers get in South Burlington, VT?

The average high peaks at 82 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 05403 have?

The USDA soil survey maps Vergennes at the center of ZIP 05403: clay, moderately well drained, pH about 5.9 (moderately acidic).

Did spring come early in South Burlington, VT in 2026?

Spring leaf-out near 05403 came on Apr 16 in 2026, about the same as the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in South Burlington, VT?

Long-day onions: the longest day near 05403 is 15 h 33 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).