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

Planting zone for 59745 — Norris, MT

ZIP code 59745 (Norris, Madison County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 30 and the first fall frost October 10.

Where ZIP 59745 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.

Zone5a−20 to −15 °F

Coldest night−28.9 to −26.1 °C

Last frostApr 30

First frostOct 10

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 Norris, 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 Norris, MT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 30median — 50% chance of a later frost

Safe for tender plantsMay 14only 10% chance of frost after

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

Growing season162 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 17 and returns around October 22.

From the NOAA station Norris Madison Pwr House, MT — 7 miles away, elevation 4,744 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 59745

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 19 – Apr 2

SpinachSow outdoors · Mar 19 – Apr 9

Broccoli, cabbageStart indoors · Feb 19 – Mar 5

Broccoli, cabbageTransplant · Apr 9 – Apr 23

Onion setsPlant outdoors · Apr 2 – Apr 16

PotatoesPlant outdoors · Apr 9 – Apr 23

LettuceSow outdoors · Apr 2 – Apr 16

Carrots, beetsSow outdoors · Apr 9 – Apr 23

TomatoesStart indoors · Mar 5 – Mar 19

TomatoesTransplant · May 7 – May 21

Peppers, eggplantStart indoors · Feb 19 – Mar 5

Peppers, eggplantTransplant · May 14 – May 28

BeansSow outdoors · May 7 – May 21

Sweet cornSow outdoors · May 7 – May 21

Cucumbers, squashSow outdoors · May 7 – May 21

Fall lettuce, spinachSow outdoors · Aug 15 – Aug 29

GarlicPlant cloves · Sep 26 – Oct 31

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 10) 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 59745 came on Mar 13 — 34 days earlier than the 1991–2020 average (Apr 16).

average
Apr 162026
Mar 13

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 Montana

548 plants native to the lower 48 states, recorded in Montana, 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 Norris, MT.

Soil in Norris, MT

The soil mapped at the center of ZIP 59745 is Shurley — very flaggy coarse sandy loam, well drained.

TextureVery flaggy coarse sandy loamdrains and warms fast; dries out and needs more feeding

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

DrainageWell drainednatural drainage class

Organic matter1.4%low — add compost

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Shurley-Rock outcrop complex, 25 to 60 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 59745; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Norris, MT

Summer high85 °Faverage high, July

Winter low24 °Faverage low, January

Hot days21days a year at 90 °F or more

Freezing nights127nights a year at 32 °F or less

Growing degree days2,416base 50 °F — the season’s usable heat

Longest day15 h 42 mindaylight on June 21

Shortest day8 h 41 mindaylight on December 21

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

Precipitation18.4 inper year, rain and melted snow

Snowfall52 inper year; 61 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: Norris Madison Pwr House, MT (7 mi away); precipitation: Norris Madison Pwr House, MT (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

597605a

Willow Creek, MT · 11 mi

597405a

Mc Allister, MT · 12 mi

597355a

Harrison, MT · 12 mi

597415a

Manhattan, MT · 17 mi

Three Forks, MT · 23 mi

Montana planting zones →

Questions about 59745

What planting zone is ZIP code 59745?

ZIP code 59745 (Norris, MT) 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 Norris, MT?

The median last spring frost (32 °F) near 59745 is April 30; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Norris Madison Pwr House station.

When is the first frost in Norris, MT?

The median first fall frost near 59745 is October 10, giving a median frost-free growing season of 162 days.

When should I plant tomatoes in 59745?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 59745 get?

About 18.4 inches of precipitation a year and 52 inches of snowfall (NOAA 1991–2020 normals, Norris Madison Pwr House station).

How hot do summers get in Norris, MT?

The average high peaks at 85 °F in July, with about 21 days a year at 90 °F or more.

What kind of soil does 59745 have?

The USDA soil survey maps Shurley at the center of ZIP 59745: very flaggy coarse sandy loam, well drained, pH about 7.5 (slightly alkaline).

Did spring come early in Norris, MT in 2026?

Spring leaf-out near 59745 came on Mar 13 in 2026, 34 days earlier than the 1991–2020 average (Apr 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Norris, MT?

Long-day onions: the longest day near 59745 is 15 h 42 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).