Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for 83328 — Filer, ID

ZIP code 83328 (Filer, Twin Falls County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 25 and the first fall frost October 15.

Where ZIP 83328 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 25

First frostOct 15

2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Filer, 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 Filer, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 25median — 50% chance of a later frost

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

First fall frostOctober 15median — 10% chance by Sep 29

Growing season172 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around October 26.

From the NOAA station Buhl #2, ID — 7 miles away, elevation 3,799 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 83328

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 14 – Mar 28

SpinachSow outdoors · Mar 14 – Apr 4

Broccoli, cabbageStart indoors · Feb 14 – Feb 28

Broccoli, cabbageTransplant · Apr 4 – Apr 18

Onion setsPlant outdoors · Mar 28 – Apr 11

PotatoesPlant outdoors · Apr 4 – Apr 18

LettuceSow outdoors · Mar 28 – Apr 11

Carrots, beetsSow outdoors · Apr 4 – Apr 18

TomatoesStart indoors · Feb 28 – Mar 14

TomatoesTransplant · May 2 – May 16

Peppers, eggplantStart indoors · Feb 14 – Feb 28

Peppers, eggplantTransplant · May 9 – May 23

BeansSow outdoors · May 2 – May 16

Sweet cornSow outdoors · May 2 – May 16

Cucumbers, squashSow outdoors · May 2 – May 16

Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3

GarlicPlant cloves · Oct 1 – Nov 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 15) 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 83328 came on Mar 7 — 19 days earlier than the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 7

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 Filer, ID.

Soil in Filer, ID

The soil mapped at the center of ZIP 83328 is Portneuf — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH7.9alkaline; 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 irrigated and reclaimed of excess salts and sodiumUSDA classification

Map unit: Portneuf silt loam, 0 to 2 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 83328; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Filer, ID

Summer high88 °Faverage high, July

Winter low22 °Faverage low, January

Hot days32days a year at 90 °F or more

Freezing nights144nights a year at 32 °F or less

Growing degree days2,719base 50 °F — the season’s usable heat

Longest day15 h 19 mindaylight on June 21

Shortest day9 h 03 mindaylight on December 21

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

Precipitation11.4 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: Buhl #2, ID (7 mi away); precipitation: Twin Falls 4.9 Wsw, ID (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

833036b

Twin Falls, ID · 8 mi

833016b

Twin Falls, ID · 13 mi

Castleford, ID · 19 mi

Idaho planting zones →

Questions about 83328

What planting zone is ZIP code 83328?

ZIP code 83328 (Filer, 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 Filer, ID?

The median last spring frost (32 °F) near 83328 is April 25; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Buhl #2 station.

When is the first frost in Filer, ID?

The median first fall frost near 83328 is October 15, giving a median frost-free growing season of 172 days.

When should I plant tomatoes in 83328?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 83328 get?

About 11.4 inches of precipitation a year (NOAA 1991–2020 normals, Twin Falls 4.9 Wsw station).

How hot do summers get in Filer, ID?

The average high peaks at 88 °F in July, with about 32 days a year at 90 °F or more.

What kind of soil does 83328 have?

The USDA soil survey maps Portneuf at the center of ZIP 83328: silt loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Filer, ID in 2026?

Spring leaf-out near 83328 came on Mar 7 in 2026, 19 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Filer, ID?

Long-day onions: the longest day near 83328 is 15 h 19 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 83328 change?

Yes. The 2012 USDA map put 83328 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.