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

Idaho planting zones

Idaho spans USDA zones 4a to 7b on the 2023 map; the most common is 6b. The typical last spring frost is around May 13 and the first fall frost around Sep 30.

Zone map of Idaho

Outside Idaho is dimmed · 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.

ZIP codes per zone

4a−30 to −25 °F24b−25 to −20 °F25a−20 to −15 °F405b−15 to −10 °F446a−10 to −5 °F526b−5 to 0 °F877a0 to 5 °F827b5 to 10 °F3

At a glance

ZIP codes312
Zones4a–7b
Typical last frostMay 13
Typical first frostSep 30

Largest cities in Idaho

Boise6b 7a
Last frost Apr 24 · first Oct 21 · 26 ZIPs
Idaho Falls5b
Last frost May 9 · first Oct 1 · 7 ZIPs
Pocatello6a 6b
Last frost May 2 · first Oct 11 · 6 ZIPs
Nampa7a
Last frost Apr 29 · first Oct 13 · 5 ZIPs
Caldwell7a
Last frost Apr 29 · first Oct 13 · 3 ZIPs
Coeur d'Alene6b 7a
Last frost Apr 22 · first Oct 18 · 3 ZIPs
Meridian7a
Last frost Apr 24 · first Oct 21 · 3 ZIPs
Rexburg5a
Last frost May 12 · first Sep 24 · 3 ZIPs
Moscow6b
Last frost Apr 29 · first Oct 2 · 2 ZIPs
Post Falls6b
Last frost Apr 22 · first Oct 18 · 2 ZIPs
Sun Valley5b
Last frost May 13 · first Oct 2 · 2 ZIPs
Twin Falls6b
Last frost May 9 · first Oct 4 · 2 ZIPs

Idaho extremes

From the 2023 zone data and NOAA 1991–2020 normals of the nearest station. One entry per town.

Mildest winters

highest zone

  1. Lewiston 835017b
  2. Juliaetta 835357b
  3. Lapwai 835407b
  4. Bliss 833147a
  5. Buhl 833167a
  6. Filer 833287a

Coldest winters

lowest zone

  1. Island Park 834294a
  2. Macks Inn 834334a
  3. Monteview 834354b
  4. Terreton 834504b
  5. Arco 832135a
  6. Bancroft 832175a

Longest growing season

median frost-free days

  1. Cambridge 83610216 d
  2. Lewiston 83501200 d
  3. Juliaetta 83535200 d
  4. Genesee 83832200 d
  5. Payette 83661183 d
  6. Ahsahka 83520182 d

Shortest growing season

median frost-free days

  1. Wayan 8328571 d
  2. Lake Fork 8363572 d
  3. Bern 8322077 d
  4. Geneva 8323877 d
  5. Georgetown 8323977 d
  6. Montpelier 8325477 d

Wettest

precipitation per year

  1. Hope 8383687.5 in
  2. Bayview 8380358.2 in
  3. Clark Fork 8381158.2 in
  4. Pierce 8354656.6 in
  5. Fernwood 8383056.1 in
  6. Santa 8386656.1 in

Snowiest

snowfall per year

  1. Elk City 83525119 in
  2. Placerville 83666117 in
  3. Sun Valley 83353102 in
  4. Bern 8322091 in
  5. Paris 8326191 in
  6. Craigmont 8352387 in

Hottest summers

days at 90 °F or more

  1. Glenns Ferry 8362382 d
  2. Hammett 8362782 d
  3. King Hill 8363382 d
  4. Bliss 8331469 d
  5. Hagerman 8333269 d
  6. Cambridge 8361068 d

All places in Idaho

A

Aberdeen · Ahsahka · Albion · Almo · American Falls · Arbon · Arco · Arimo · Ashton · Athol · Avery

B

Bancroft · Banks · Basalt · Bayview · Bellevue · Bern · Blackfoot · Blanchard · Bliss · Bloomington · Boise · Bonners Ferry · Bovill · Bruneau · Buhl · Burley

C

Calder · Caldwell · Cambridge · Carey · Careywood · Carmen · Cascade · Castleford · Cataldo · Challis · Chester · Clark Fork · Clarkia · Clayton · Clifton · Cobalt · Cocolalla · Coeur d'Alene · Colburn · Coolin · Corral · Cottonwood · Council · Craigmont · Culdesac

D

Dayton · Deary · Declo · Desmet · Dietrich · Dingle · Donnelly · Dover · Downey · Driggs · Dubois

E

Eagle · Eastport · Eden · Elk City · Elk River · Ellis · Emmett

F

Fairfield · Felt · Fenn · Ferdinand · Fernwood · Filer · Firth · Fish Haven · Fort Hall · Franklin · Fruitland

G

Garden City · Garden Valley · Genesee · Geneva · Georgetown · Gibbonsville · Glenns Ferry · Gooding · Grace · Grand View · Grangeville · Greencreek · Greenleaf

H

Hagerman · Hailey · Hamer · Hammett · Hansen · Harrison · Harvard · Hayden · Hazelton · Heyburn · Hill City · Holbrook · Homedale · Hope · Horseshoe Bend · Howe · Huston

I

Idaho City · Idaho Falls · Indian Valley · Inkom · Iona · Irwin · Island Park

J

Jerome · Juliaetta

K

Kamiah · Kellogg · Kendrick · Ketchum · Kimberly · King Hill · Kingston · Kooskia · Kootenai · Kuna

L

Laclede · Lake Fork · Lapwai · Lava Hot Springs · Leadore · Lemhi · Lenore · Letha · Lewiston · Lewisville · Lowman · Lucile

M

Mackay · Macks Inn · Malad City · Malta · Marsing · May · McCall · McCammon · Medimont · Melba · Menan · Meridian · Mesa · Middleton · Midvale · Minidoka · Monteview · Montpelier · Moore · Moscow · Mountain Home · Mountain Home Afb · Moyie Springs · Mullan · Murphy · Murray · Murtaugh

N

Nampa · Naples · New Meadows · New Plymouth · Newdale · Nezperce · Nordman · North Fork · Notus

O

Oakley · Ola · Oldtown · Orofino · Osburn

P

Paris · Parker · Parma · Paul · Payette · Peck · Picabo · Pierce · Pinehurst · Pingree · Placerville · Plummer · Pocatello · Pollock · Ponderay · Post Falls · Potlatch · Preston · Priest River · Princeton

R

Rathdrum · Reubens · Rexburg · Richfield · Rigby · Riggins · Ririe · Roberts · Rockland · Rogerson · Rupert

S

Sagle · Saint Anthony · Saint Charles · Saint Maries · Salmon · Sandpoint · Santa · Shelley · Shoshone · Shoup · Silverton · Smelterville · Soda Springs · Spencer · Spirit Lake · Springfield · Stanley · Star · Stites · Sugar City · Sun Valley · Swan Valley · Swanlake · Sweet

T

Tendoy · Tensed · Terreton · Teton · Tetonia · Thatcher · Troy · Twin Falls

V

Victor · Viola

W

Wallace · Warren · Wayan · Weippe · Weiser · Wendell · Weston · White Bird · Wilder · Winchester · Worley

Y

Yellow Pine

Questions

What planting zones are in Idaho?

Idaho spans USDA hardiness zones 4a to 7b on the 2023 map. The most common zone is 6b (87 of 312 ZIP codes).

When is the last frost in Idaho?

Across Idaho, the median last spring frost ranges from about Apr 2 to Jun 22 depending on location; the typical ZIP code sees it around May 13. Look up your ZIP code for a local date.