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

Planting zone for 83241 — Grace, ID

ZIP code 83241 (Grace, Caribou County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 29 and the first fall frost September 17.

Where ZIP 83241 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostMay 29

First frostSep 17

2012 zone5a

Was 5a 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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Grace, ID…

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 Grace, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

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

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

First fall frostSeptember 17median — 10% chance by Sep 1

Growing season111 daysfrost-free, median

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

From the NOAA station Grace, ID — 6 miles away, elevation 5,551 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 83241

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 17 – May 1

SpinachSow outdoors · Apr 17 – May 8

Broccoli, cabbageStart indoors · Mar 20 – Apr 3

Broccoli, cabbageTransplant · May 8 – May 22

Onion setsPlant outdoors · May 1 – May 15

PotatoesPlant outdoors · May 8 – May 22

LettuceSow outdoors · May 1 – May 15

Carrots, beetsSow outdoors · May 8 – May 22

TomatoesStart indoors · Apr 3 – Apr 17

TomatoesTransplant · Jun 5 – Jun 19

Peppers, eggplantStart indoors · Mar 20 – Apr 3

Peppers, eggplantTransplant · Jun 12 – Jun 26

BeansSow outdoors · Jun 5 – Jun 19

Sweet cornSow outdoors · Jun 5 – Jun 19

Cucumbers, squashSow outdoors · Jun 5 – Jun 19

Fall lettuce, spinachSow outdoors · Jul 23 – Aug 6

GarlicPlant cloves · Sep 3 – Oct 8

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 29) and first fall frost (Sep 17) 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 83241 came on Mar 23 — 26 days earlier than the 1991–2020 average (Apr 18).

average
Apr 182026
Mar 23

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 Grace, ID

The soil mapped at the center of ZIP 83241 is Cedarhill — gravelly silt loam, well drained.

TextureGravelly silt loama good balance for most vegetables

pH7.5slightly alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Cedarhill, extremely stony surfface-Rubble land-Kackley, extremely stony surface, complex, 5 to 30 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 83241; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Grace, ID

Summer high85 °Faverage high, July

Winter low13 °Faverage low, January

Hot days25days a year at 90 °F or more

Freezing nights200nights a year at 32 °F or less

Growing degree days1,749base 50 °F — the season’s usable heat

Longest day15 h 18 mindaylight on June 21

Shortest day9 h 03 mindaylight on December 21

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

Precipitation15.1 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Grace, ID (6 mi away); precipitation: Grace, ID (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

832836a

Thatcher, ID · 12 mi

832466b

Lava Hot Springs, ID · 15 mi

Georgetown, ID · 21 mi

Idaho planting zones →

Questions about 83241

What planting zone is ZIP code 83241?

ZIP code 83241 (Grace, ID) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Grace, ID?

The median last spring frost (32 °F) near 83241 is May 29; after June 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Grace station.

When is the first frost in Grace, ID?

The median first fall frost near 83241 is September 17, giving a median frost-free growing season of 111 days.

When should I plant tomatoes in 83241?

Start tomato seeds indoors around Apr 3 – Apr 17 and set transplants outside around Jun 5 – Jun 19, one to three weeks after the median last frost.

How much rain and snow does 83241 get?

About 15.1 inches of precipitation a year (NOAA 1991–2020 normals, Grace station).

How hot do summers get in Grace, ID?

The average high peaks at 85 °F in July, with about 25 days a year at 90 °F or more.

What kind of soil does 83241 have?

The USDA soil survey maps Cedarhill at the center of ZIP 83241: gravelly silt loam, well drained, pH about 7.5 (slightly alkaline).

Did spring come early in Grace, ID in 2026?

Spring leaf-out near 83241 came on Mar 23 in 2026, 26 days earlier than the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Grace, ID?

Long-day onions: the longest day near 83241 is 15 h 18 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 83241 change?

Yes. The 2012 USDA map put 83241 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.