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

Planting zone for Nampa, ID

Nampa, ID is in USDA zone 7a across its 5 ZIP codes. The median last spring frost is April 29 and the first fall frost October 13.

Nampa on the zone map

Outlined: its 3 ZIP code areas · 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.

Zone7a0 to 5 °F
ZIP codes5
Last frostApr 29
First frostOct 13
Growing season164 days

7a 5 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Nampa, 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 Nampa, ID

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 29median — 50% chance of a later frost
Safe for tender plantsMay 18only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Sep 29
Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 11 and returns around October 25.

From the NOAA station Nampa Sugar Factory, ID, elevation 2,471 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 Nampa

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 18 – Apr 1
SpinachSow outdoors · Mar 18 – Apr 8
Broccoli, cabbageStart indoors · Feb 18 – Mar 4
Broccoli, cabbageTransplant · Apr 8 – Apr 22
Onion setsPlant outdoors · Apr 1 – Apr 15
PotatoesPlant outdoors · Apr 8 – Apr 22
LettuceSow outdoors · Apr 1 – Apr 15
Carrots, beetsSow outdoors · Apr 8 – Apr 22
TomatoesStart indoors · Mar 4 – Mar 18
TomatoesTransplant · May 6 – May 20
Peppers, eggplantStart indoors · Feb 18 – Mar 4
Peppers, eggplantTransplant · May 13 – May 27
BeansSow outdoors · May 6 – May 20
Sweet cornSow outdoors · May 6 – May 20
Cucumbers, squashSow outdoors · May 6 – May 20
Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1
GarlicPlant cloves · Sep 29 – Nov 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 13) 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 83651 came on Mar 5 — 14 days earlier than the 1991–2020 average (Mar 19).

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 7a in Idaho

575 plants native to the lower 48 states, recorded in Idaho, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 30

balsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblue spruce100 ft · blooms late spring · medium shade tolerance · to −38 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °FDouglas-fir200 ft · blooms mid spring · medium shade tolerance · to −33 °FEngelmann spruce120 ft · blooms late spring · low shade tolerance · to −50 °F

Shrubs 101

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FBarclay's willow15 ft · high shade tolerance · to −43 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °F

Wildflowers & perennials 277

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 155

Alaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAlpine Meadow-Foxtail0.5 ft · blooms mid spring · medium shade tolerance · to −33 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °F

Vines 1

western white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 Nampa, ID.

Soil in Nampa, ID

The soil mapped at the center of ZIP 83651 is Power — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Power silt loam, 0 to 1 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 83651; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Nampa, ID

Summer high93 °Faverage high, July
Winter low23 °Faverage low, January
Hot days59days a year at 90 °F or more
Freezing nights132nights a year at 32 °F or less
Growing degree days2,956base 50 °F — the season’s usable heat
Longest day15 h 26 mindaylight on June 21
Shortest day8 h 56 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation11 inper year, rain and melted snow
Snowfall10 inper year; 12 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 40 °F, low 23 °F 40°23° JanFebruary: average high 47 °F, low 26 °F 47°26° FebMarch: average high 57 °F, low 32 °F 57°32° MarApril: average high 65 °F, low 36 °F 65°36° AprMay: average high 74 °F, low 44 °F 74°44° MayJune: average high 83 °F, low 51 °F 83°51° JunJuly: average high 93 °F, low 57 °F 93°57° JulAugust: average high 92 °F, low 56 °F 92°56° AugSeptember: average high 81 °F, low 47 °F 81°47° SepOctober: average high 67 °F, low 37 °F 67°37° OctNovember: average high 51 °F, low 28 °F 51°28° NovDecember: average high 40 °F, low 23 °F 40°23° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 1.37 in precipitation, 3.4 in snowfall 1.4❄3 JanFebruary: 1.04 in precipitation, 1.4 in snowfall 1.0❄1 FebMarch: 1.26 in precipitation, 0.2 in snowfall 1.3 MarApril: 1.06 in precipitation 1.1 AprMay: 1.37 in precipitation 1.4 MayJune: 0.73 in precipitation 0.7 JunJuly: 0.26 in precipitation 0.3 JulAugust: 0.20 in precipitation 0.2 AugSeptember: 0.36 in precipitation 0.4 SepOctober: 0.80 in precipitation 0.8 OctNovember: 1.17 in precipitation, 0.5 in snowfall 1.2❄1 NovDecember: 1.39 in precipitation, 4.2 in snowfall 1.4❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Nampa Sugar Factory, ID (3 mi away); precipitation: Nampa Sugar Factory, ID (3 mi away). Daylight is calculated from latitude.

ZIP codes in Nampa

836517a
0 to 5 °F
836527a
0 to 5 °F
836537a
0 to 5 °F
836867a
0 to 5 °F
836877a
0 to 5 °F

Idaho planting zones →

Questions about Nampa

What planting zone is Nampa, ID?

Nampa, ID is in USDA hardiness zone 7a on the 2023 map (7a: 0 to 5 °F).

When is the last frost in Nampa, ID?

The median last spring frost is April 29 and the median first fall frost is October 13 (NOAA 1991–2020 normals, Nampa Sugar Factory station).

When can I plant a garden in Nampa, ID?

Cool-season crops like peas and spinach go in around Mar 18 – Apr 8; tomatoes, peppers, beans and squash after about May 6, once frost risk has passed.

What kind of onions grow in Nampa, ID?

Long-day onions: the longest day is 15 h 26 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Nampa, ID get?

About 11 inches of precipitation a year and 10 inches of snowfall (NOAA 1991–2020 normals).