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

Planting zone for 47670 — Princeton, IN

ZIP code 47670 (Princeton, Gibson County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 13 and the first fall frost October 25.

Where ZIP 47670 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 13
First frostOct 25
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 Princeton, IN…

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 Princeton, IN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 13median — 50% chance of a later frost
Safe for tender plantsApril 30only 10% chance of frost after
First fall frostOctober 25median — 10% chance by Oct 10
Growing season194 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 3.

From the NOAA station Princeton 1 W, IN — within 1 mile, elevation 479 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 47670

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 2 – Mar 16
SpinachSow outdoors · Mar 2 – Mar 23
Broccoli, cabbageStart indoors · Feb 2 – Feb 16
Broccoli, cabbageTransplant · Mar 23 – Apr 6
Onion setsPlant outdoors · Mar 16 – Mar 30
PotatoesPlant outdoors · Mar 23 – Apr 6
LettuceSow outdoors · Mar 16 – Mar 30
Carrots, beetsSow outdoors · Mar 23 – Apr 6
TomatoesStart indoors · Feb 16 – Mar 2
TomatoesTransplant · Apr 20 – May 4
Peppers, eggplantStart indoors · Feb 2 – Feb 16
Peppers, eggplantTransplant · Apr 27 – May 11
BeansSow outdoors · Apr 20 – May 4
Sweet cornSow outdoors · Apr 20 – May 4
Cucumbers, squashSow outdoors · Apr 20 – May 4
Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13
GarlicPlant cloves · Oct 11 – Nov 15
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 13) and first fall frost (Oct 25) 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 47670 came on Mar 6 — 9 days earlier than the 1991–2020 average (Mar 15).

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 Princeton, IN

The soil mapped at the center of ZIP 47670 is Alford — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Alford silt loam, 10 to 18 percent slopes, severely eroded.

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 47670; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Princeton, IN

Summer high88 °Faverage high, July
Winter low21 °Faverage low, January
Hot days38days a year at 90 °F or more
Freezing nights100nights a year at 32 °F or less
Growing degree days3,980base 50 °F — the season’s usable heat
Longest day14 h 50 mindaylight on June 21
Shortest day9 h 29 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation49.8 inper year, rain and melted snow
Snowfall12 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 40 °F, low 21 °F 40°21° JanFebruary: average high 45 °F, low 24 °F 45°24° FebMarch: average high 55 °F, low 32 °F 55°32° MarApril: average high 67 °F, low 43 °F 67°43° AprMay: average high 77 °F, low 54 °F 77°54° MayJune: average high 85 °F, low 63 °F 85°63° JunJuly: average high 88 °F, low 66 °F 88°66° JulAugust: average high 87 °F, low 64 °F 87°64° AugSeptember: average high 81 °F, low 57 °F 81°57° SepOctober: average high 69 °F, low 45 °F 69°45° OctNovember: average high 55 °F, low 33 °F 55°33° NovDecember: average high 44 °F, low 26 °F 44°26° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 3.39 in precipitation, 3.6 in snowfall 3.4❄4 JanFebruary: 3.21 in precipitation, 3.4 in snowfall 3.2❄3 FebMarch: 4.54 in precipitation, 1.2 in snowfall 4.5❄1 MarApril: 5.27 in precipitation 5.3 AprMay: 5.67 in precipitation 5.7 MayJune: 4.46 in precipitation 4.5 JunJuly: 4.53 in precipitation 4.5 JulAugust: 3.32 in precipitation 3.3 AugSeptember: 4.20 in precipitation 4.2 SepOctober: 3.41 in precipitation, 0.1 in snowfall 3.4 OctNovember: 4.07 in precipitation, 0.2 in snowfall 4.1 NovDecember: 3.77 in precipitation, 3.7 in snowfall 3.8❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Princeton 1 W, IN (within 1 mile); precipitation: Princeton 1 W, IN (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

476666b
Patoka, IN · 5 mi
476496b
Francisco, IN · 7 mi
476487a
Fort Branch, IN · 7 mi
476656b
Owensville, IN · 10 mi
475246b
Decker, IN · 10 mi
476406b
Hazleton, IN · 10 mi
476397a
Haubstadt, IN · 11 mi
476837a
Somerville, IN · 12 mi

Indiana planting zones →

Questions about 47670

What planting zone is ZIP code 47670?

ZIP code 47670 (Princeton, IN) 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 Princeton, IN?

The median last spring frost (32 °F) near 47670 is April 13; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Princeton 1 W station.

When is the first frost in Princeton, IN?

The median first fall frost near 47670 is October 25, giving a median frost-free growing season of 194 days.

When should I plant tomatoes in 47670?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 47670 get?

About 49.8 inches of precipitation a year and 12 inches of snowfall (NOAA 1991–2020 normals, Princeton 1 W station).

How hot do summers get in Princeton, IN?

The average high peaks at 88 °F in July, with about 38 days a year at 90 °F or more.

What kind of soil does 47670 have?

The USDA soil survey maps Alford at the center of ZIP 47670: silt loam, well drained, pH about 5.9 (moderately acidic).

Did spring come early in Princeton, IN in 2026?

Spring leaf-out near 47670 came on Mar 6 in 2026, 9 days earlier than the 1991–2020 average (Mar 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Princeton, IN?

Intermediate onions: the longest day near 47670 is 14 h 50 min, so day-neutral types bulb best; long-day varieties may not bulb fully.