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

Planting zone for 46147 — Jamestown, IN

ZIP code 46147 (Jamestown, Boone County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 23 and the first fall frost October 19.

Where ZIP 46147 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 23
First frostOct 19
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Jamestown, 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 Jamestown, IN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 23median — 50% chance of a later frost
Safe for tender plantsMay 9only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 4
Growing season178 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around November 1.

From the NOAA station Jamestown 2 E, IN — 4 miles away, elevation 961 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 46147

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 12 – Mar 26
SpinachSow outdoors · Mar 12 – Apr 2
Broccoli, cabbageStart indoors · Feb 12 – Feb 26
Broccoli, cabbageTransplant · Apr 2 – Apr 16
Onion setsPlant outdoors · Mar 26 – Apr 9
PotatoesPlant outdoors · Apr 2 – Apr 16
LettuceSow outdoors · Mar 26 – Apr 9
Carrots, beetsSow outdoors · Apr 2 – Apr 16
TomatoesStart indoors · Feb 26 – Mar 12
TomatoesTransplant · Apr 30 – May 14
Peppers, eggplantStart indoors · Feb 12 – Feb 26
Peppers, eggplantTransplant · May 7 – May 21
BeansSow outdoors · Apr 30 – May 14
Sweet cornSow outdoors · Apr 30 – May 14
Cucumbers, squashSow outdoors · Apr 30 – May 14
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 23) and first fall frost (Oct 19) 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 46147 came on Mar 10 — 18 days earlier than the 1991–2020 average (Mar 28).

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 6a in Indiana

558 plants native to the lower 48 states, recorded in Indiana, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 71

Shrubs 105

Wildflowers & perennials 200

Grasses 161

Vines 9

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 Jamestown, IN.

Soil in Jamestown, IN

The soil mapped at the center of ZIP 46147 is Miami — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Miami silt loam, 2 to 6 percent slopes, 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 46147; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Jamestown, IN

Summer high83 °Faverage high, July
Winter low18 °Faverage low, January
Hot days11days a year at 90 °F or more
Freezing nights127nights a year at 32 °F or less
Growing degree days3,243base 50 °F — the season’s usable heat
Longest day15 h 01 mindaylight on June 21
Shortest day9 h 20 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation43.3 inper year, rain and melted snow
Snowfall14 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 34 °F, low 18 °F 34°18° JanFebruary: average high 38 °F, low 21 °F 38°21° FebMarch: average high 49 °F, low 30 °F 49°30° MarApril: average high 62 °F, low 40 °F 62°40° AprMay: average high 72 °F, low 51 °F 72°51° MayJune: average high 80 °F, low 60 °F 80°60° JunJuly: average high 83 °F, low 63 °F 83°63° JulAugust: average high 82 °F, low 61 °F 82°61° AugSeptember: average high 77 °F, low 54 °F 77°54° SepOctober: average high 65 °F, low 43 °F 65°43° OctNovember: average high 51 °F, low 32 °F 51°32° NovDecember: average high 39 °F, low 23 °F 39°23° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 2.59 in precipitation, 5 in snowfall 2.6❄5 JanFebruary: 2.38 in precipitation, 2 in snowfall 2.4❄2 FebMarch: 3.12 in precipitation, 2.2 in snowfall 3.1❄2 MarApril: 4.49 in precipitation, 0.2 in snowfall 4.5 AprMay: 4.90 in precipitation 4.9 MayJune: 5.16 in precipitation 5.2 JunJuly: 4.46 in precipitation 4.5 JulAugust: 3.25 in precipitation 3.3 AugSeptember: 3.33 in precipitation 3.3 SepOctober: 3.53 in precipitation 3.5 OctNovember: 3.33 in precipitation, 0.8 in snowfall 3.3❄1 NovDecember: 2.72 in precipitation, 3.8 in snowfall 2.7❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Jamestown 2 E, IN (4 mi away); precipitation: Jamestown 2 E, IN (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

Indiana planting zones →

Questions about 46147

What planting zone is ZIP code 46147?

ZIP code 46147 (Jamestown, IN) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Jamestown, IN?

The median last spring frost (32 °F) near 46147 is April 23; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Jamestown 2 E station.

When is the first frost in Jamestown, IN?

The median first fall frost near 46147 is October 19, giving a median frost-free growing season of 178 days.

When should I plant tomatoes in 46147?

Start tomato seeds indoors around Feb 26 – Mar 12 and set transplants outside around Apr 30 – May 14, one to three weeks after the median last frost.

How much rain and snow does 46147 get?

About 43.3 inches of precipitation a year and 14 inches of snowfall (NOAA 1991–2020 normals, Jamestown 2 E station).

How hot do summers get in Jamestown, IN?

The average high peaks at 83 °F in July, with about 11 days a year at 90 °F or more.

What kind of soil does 46147 have?

The USDA soil survey maps Miami at the center of ZIP 46147: silt loam, moderately well drained, pH about 6.5 (neutral).

Did spring come early in Jamestown, IN in 2026?

Spring leaf-out near 46147 came on Mar 10 in 2026, 18 days earlier than the 1991–2020 average (Mar 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Jamestown, IN?

Long-day onions: the longest day near 46147 is 15 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 46147 change?

Yes. The 2012 USDA map put 46147 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.