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

Planting zone for 59452 — Hobson, MT

ZIP code 59452 (Hobson, Judith Basin County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is June 15 and the first fall frost September 4.

Where ZIP 59452 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostJun 15

First frostSep 4

2012 zone4a

Was 4a 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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hobson, 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 Hobson, MT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 15median — 50% chance of a later frost

Safe for tender plantsJuly 8only 10% chance of frost after

First fall frostSeptember 4median — 10% chance by Aug 19

Growing season77 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 25 and returns around September 18.

From the NOAA station Lewistown 42 Wsw, MT — 11 miles away, elevation 5,069 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 59452

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · May 4 – May 18

SpinachSow outdoors · May 4 – May 25

Broccoli, cabbageStart indoors · Apr 6 – Apr 20

Broccoli, cabbageTransplant · May 25 – Jun 8

Onion setsPlant outdoors · May 18 – Jun 1

PotatoesPlant outdoors · May 25 – Jun 8

LettuceSow outdoors · May 18 – Jun 1

Carrots, beetsSow outdoors · May 25 – Jun 8

TomatoesStart indoors · Apr 20 – May 4

TomatoesTransplant · Jun 22 – Jul 6

Peppers, eggplantStart indoors · Apr 6 – Apr 20

Peppers, eggplantTransplant · Jun 29 – Jul 13

BeansSow outdoors · Jun 22 – Jul 6

Sweet cornSow outdoors · Jun 22 – Jul 6

Cucumbers, squashSow outdoors · Jun 22 – Jul 6

Fall lettuce, spinachSow outdoors · Jul 10 – Jul 24

GarlicPlant cloves · Aug 21 – Sep 25

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 15) and first fall frost (Sep 4) 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 59452 came on Mar 24 — 27 days earlier than the 1991–2020 average (Apr 20).

average
Apr 202026
Mar 24

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 Hobson, MT

The soil mapped at the center of ZIP 59452 is Darret — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up

pH7.2neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Darret-Utica complex.

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 59452; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hobson, MT

Summer high78 °Faverage high, July

Winter low12 °Faverage low, February

Hot days4days a year at 90 °F or more

Freezing nights212nights a year at 32 °F or less

Growing degree days1,040base 50 °F — the season’s usable heat

Longest day15 h 53 mindaylight on June 21

Shortest day8 h 31 mindaylight on December 21

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

Precipitation16.8 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: Lewistown 42 Wsw, MT (11 mi away); precipitation: Lewistown 42 Wsw, MT (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

Judith Gap, MT · 25 mi

594654b

Neihart, MT · 31 mi

590364b

Harlowton, MT · 31 mi

594244b

Coffee Creek, MT · 32 mi

Montana planting zones →

Questions about 59452

What planting zone is ZIP code 59452?

ZIP code 59452 (Hobson, MT) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Hobson, MT?

The median last spring frost (32 °F) near 59452 is June 15; after July 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lewistown 42 Wsw station.

When is the first frost in Hobson, MT?

The median first fall frost near 59452 is September 4, giving a median frost-free growing season of 77 days.

When should I plant tomatoes in 59452?

Start tomato seeds indoors around Apr 20 – May 4 and set transplants outside around Jun 22 – Jul 6, one to three weeks after the median last frost.

How much rain and snow does 59452 get?

About 16.8 inches of precipitation a year (NOAA 1991–2020 normals, Lewistown 42 Wsw station).

How hot do summers get in Hobson, MT?

The average high peaks at 78 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 59452 have?

The USDA soil survey maps Darret at the center of ZIP 59452: clay loam, well drained, pH about 7.2 (neutral).

Did spring come early in Hobson, MT in 2026?

Spring leaf-out near 59452 came on Mar 24 in 2026, 27 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hobson, MT?

Long-day onions: the longest day near 59452 is 15 h 53 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 59452 change?

Yes. The 2012 USDA map put 59452 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.