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

Planting zone for 83644 — Middleton, ID

ZIP code 83644 (Middleton, Canyon County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 30 and the first fall frost October 17.

Where ZIP 83644 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.

Zone7a0 to 5 °F

Coldest night−17.8 to −15 °C

Last frostApr 30

First frostOct 17

2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Middleton, 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 Middleton, ID

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 17only 10% chance of frost after

First fall frostOctober 17median — 10% chance by Oct 2

Growing season168 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 28.

From the NOAA station Emmett 2 E, ID — 9 miles away, elevation 2,392 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 83644

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 22 – Sep 5

GarlicPlant cloves · Oct 3 – Nov 7

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 17) 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 83644 came on Mar 8 — 12 days earlier than the 1991–2020 average (Mar 20).

average
Mar 202026
Mar 8

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.

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 Middleton, ID.

Soil in Middleton, ID

The soil mapped at the center of ZIP 83644 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, 1 to 3 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 83644; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Middleton, ID

Summer high92 °Faverage high, July

Winter low23 °Faverage low, January

Hot days51days a year at 90 °F or more

Freezing nights131nights a year at 32 °F or less

Growing degree days2,871base 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)

Precipitation12.3 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: Emmett 2 E, ID (9 mi away); precipitation: Middleton 0.7 Ene, ID (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

Idaho planting zones →

Questions about 83644

What planting zone is ZIP code 83644?

ZIP code 83644 (Middleton, ID) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Middleton, ID?

The median last spring frost (32 °F) near 83644 is April 30; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Emmett 2 E station.

When is the first frost in Middleton, ID?

The median first fall frost near 83644 is October 17, giving a median frost-free growing season of 168 days.

When should I plant tomatoes in 83644?

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 83644 get?

About 12.3 inches of precipitation a year (NOAA 1991–2020 normals, Middleton 0.7 Ene station).

How hot do summers get in Middleton, ID?

The average high peaks at 92 °F in July, with about 51 days a year at 90 °F or more.

What kind of soil does 83644 have?

The USDA soil survey maps Power at the center of ZIP 83644: silt loam, well drained, pH about 7.2 (neutral).

Did spring come early in Middleton, ID in 2026?

Spring leaf-out near 83644 came on Mar 8 in 2026, 12 days earlier than the 1991–2020 average (Mar 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Middleton, ID?

Long-day onions: the longest day near 83644 is 15 h 27 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).