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

Planting zone for 59930 — Rexford, MT

ZIP code 59930 (Rexford, Lincoln County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 11 and the first fall frost September 27.

Where ZIP 59930 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 11

First frostSep 27

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 Rexford, MT…

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 Rexford, MT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 11median — 50% chance of a later frost

Safe for tender plantsMay 25only 10% chance of frost after

First fall frostSeptember 27median — 10% chance by Sep 10

Growing season138 daysfrost-free, median

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

From the NOAA station Eureka Rs, MT — 4 miles away, elevation 2,533 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 59930

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 30 – Apr 13

SpinachSow outdoors · Mar 30 – Apr 20

Broccoli, cabbageStart indoors · Mar 2 – Mar 16

Broccoli, cabbageTransplant · Apr 20 – May 4

Onion setsPlant outdoors · Apr 13 – Apr 27

PotatoesPlant outdoors · Apr 20 – May 4

LettuceSow outdoors · Apr 13 – Apr 27

Carrots, beetsSow outdoors · Apr 20 – May 4

TomatoesStart indoors · Mar 16 – Mar 30

TomatoesTransplant · May 18 – Jun 1

Peppers, eggplantStart indoors · Mar 2 – Mar 16

Peppers, eggplantTransplant · May 25 – Jun 8

BeansSow outdoors · May 18 – Jun 1

Sweet cornSow outdoors · May 18 – Jun 1

Cucumbers, squashSow outdoors · May 18 – Jun 1

Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16

GarlicPlant cloves · Sep 13 – Oct 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 11) and first fall frost (Sep 27) 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 59930 came on Apr 9 — 5 days earlier than the 1991–2020 average (Apr 14).

average
Apr 142026
Apr 9

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 5b in Montana

561 plants native to the lower 48 states, recorded in Montana, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 Rexford, MT.

Soil in Rexford, MT

The soil mapped at the center of ZIP 59930 is Typic Eutrochrept — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer

pH6.5neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter50%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Typic Eutrochrepts, moraines.

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 59930; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Rexford, MT

Summer high87 °Faverage high, July

Winter low19 °Faverage low, January

Hot days26days a year at 90 °F or more

Freezing nights153nights a year at 32 °F or less

Growing degree days2,158base 50 °F — the season’s usable heat

Longest day16 h 11 mindaylight on June 21

Shortest day8 h 15 mindaylight on December 21

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

Precipitation15 inper year, rain and melted snow

Snowfall35 inper year; 56 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: Eureka Rs, MT (4 mi away); precipitation: Eureka Rs, MT (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Polebridge, MT · 39 mi

599375a

Whitefish, MT · 41 mi

Montana planting zones →

Questions about 59930

What planting zone is ZIP code 59930?

ZIP code 59930 (Rexford, MT) 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 Rexford, MT?

The median last spring frost (32 °F) near 59930 is May 11; after May 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Eureka Rs station.

When is the first frost in Rexford, MT?

The median first fall frost near 59930 is September 27, giving a median frost-free growing season of 138 days.

When should I plant tomatoes in 59930?

Start tomato seeds indoors around Mar 16 – Mar 30 and set transplants outside around May 18 – Jun 1, one to three weeks after the median last frost.

How much rain and snow does 59930 get?

About 15 inches of precipitation a year and 35 inches of snowfall (NOAA 1991–2020 normals, Eureka Rs station).

How hot do summers get in Rexford, MT?

The average high peaks at 87 °F in July, with about 26 days a year at 90 °F or more.

What kind of soil does 59930 have?

The USDA soil survey maps Typic Eutrochrept at the center of ZIP 59930: slightly decomposed plant material, well drained, pH about 6.5 (neutral).

Did spring come early in Rexford, MT in 2026?

Spring leaf-out near 59930 came on Apr 9 in 2026, 5 days earlier than the 1991–2020 average (Apr 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Rexford, MT?

Long-day onions: the longest day near 59930 is 16 h 11 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59930 change?

Yes. The 2012 USDA map put 59930 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.