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

Planting zone for 83441 — Rexburg, ID

ZIP code 83441 (Rexburg, Madison County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 12 and the first fall frost September 24.

Where ZIP 83441 is

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 12

First frostSep 24

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 Rexburg, 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 Rexburg, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 12median — 50% chance of a later frost

Safe for tender plantsJune 2only 10% chance of frost after

First fall frostSeptember 24median — 10% chance by Sep 6

Growing season132 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 7.

From the NOAA station Rexburg Byu Idaho, ID — 6 miles away, elevation 5,007 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 83441

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 31 – Apr 14

SpinachSow outdoors · Mar 31 – Apr 21

Broccoli, cabbageStart indoors · Mar 3 – Mar 17

Broccoli, cabbageTransplant · Apr 21 – May 5

Onion setsPlant outdoors · Apr 14 – Apr 28

PotatoesPlant outdoors · Apr 21 – May 5

LettuceSow outdoors · Apr 14 – Apr 28

Carrots, beetsSow outdoors · Apr 21 – May 5

TomatoesStart indoors · Mar 17 – Mar 31

TomatoesTransplant · May 19 – Jun 2

Peppers, eggplantStart indoors · Mar 3 – Mar 17

Peppers, eggplantTransplant · May 26 – Jun 9

BeansSow outdoors · May 19 – Jun 2

Sweet cornSow outdoors · May 19 – Jun 2

Cucumbers, squashSow outdoors · May 19 – Jun 2

Fall lettuce, spinachSow outdoors · Jul 30 – Aug 13

GarlicPlant cloves · Sep 10 – Oct 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 12) and first fall frost (Sep 24) 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 83441 came on Mar 28 — 24 days earlier than the 1991–2020 average (Apr 21).

average
Apr 212026
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 5a in Idaho

536 plants native to the lower 48 states, recorded in Idaho, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

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 Rexburg, ID.

Soil in Rexburg, ID

The soil mapped at the center of ZIP 83441 is Panmod — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Panmod silt loam, 4 to 12 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 83441; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Rexburg, ID

Summer high85 °Faverage high, July

Winter low14 °Faverage low, January

Hot days16days a year at 90 °F or more

Freezing nights184nights a year at 32 °F or less

Growing degree days1,948base 50 °F — the season’s usable heat

Longest day15 h 27 mindaylight on June 21

Shortest day8 h 55 mindaylight on December 21

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

Precipitation12.6 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: Rexburg Byu Idaho, ID (6 mi away); precipitation: Rexburg Byu Idaho, ID (6 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.

834485a

Sugar City, ID · 5 mi

All 3 ZIP codes in Rexburg → · Idaho planting zones →

Questions about 83441

What planting zone is ZIP code 83441?

ZIP code 83441 (Rexburg, ID) 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 Rexburg, ID?

The median last spring frost (32 °F) near 83441 is May 12; after June 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Rexburg Byu Idaho station.

When is the first frost in Rexburg, ID?

The median first fall frost near 83441 is September 24, giving a median frost-free growing season of 132 days.

When should I plant tomatoes in 83441?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 83441 get?

About 12.6 inches of precipitation a year (NOAA 1991–2020 normals, Rexburg Byu Idaho station).

How hot do summers get in Rexburg, ID?

The average high peaks at 85 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 83441 have?

The USDA soil survey maps Panmod at the center of ZIP 83441: silt loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Rexburg, ID in 2026?

Spring leaf-out near 83441 came on Mar 28 in 2026, 24 days earlier than the 1991–2020 average (Apr 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Rexburg, ID?

Long-day onions: the longest day near 83441 is 15 h 27 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).