U.S. Frost Dates by Weather Station

NOAA station USC00104831 · Idaho

Frost Dates for Kellogg, ID

NOAA weather station Kellogg (USC00104831), Idaho · elevation 2377 ft (725 m) · hardiness zone 6b*

  • Lower-risk planting dateafter June 3only 1 spring in 10 still has a frost later
  • Typical last frostMay 1450% chance of a frost after it
  • Typical first fall frostSeptember 2650% chance of a frost before it
  • Frost-free season131 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Kellogg, IDSpring: a frost after April 30 in 9 years out of 10, after May 14 in half of the years, after June 3 in 1 year out of 10. Fall: the first frost comes before September 9 in 1 year out of 10, before September 26 in half of the years, before October 9 in 9 years out of 10. Typical frost-free season: 131 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 14First frost ~Sep 26Frost season at Kellogg, IDSpring: a frost after April 30 in 9 years out of 10, after May 14 in half of the years, after June 3 in 1 year out of 10. Fall: the first frost comes before September 9 in 1 year out of 10, before September 26 in half of the years, before October 9 in 9 years out of 10. Typical frost-free season: 131 days.JFMAMJJASONDLast frost ~May 14First frost ~Sep 26
frost likely chance fading 90% → 10% frost-free in a typical yearThe year at a glance. Blue: frost is likely; the gradient fades as the chance drops from 90% to 10%; green: the frost-free part of a typical year.

Frost dates (32°F)

Probability of frost, based on 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 3September 9
50% (typical)May 14September 26
90% (likely)April 30October 9
Frost-free season (32°F, 50% chance)
131 days
Hard frost (28°F), last in spring, 50% chance after
April 30
Hard frost (28°F), first in fall, 50% chance before
October 8

The last 15 years (2006–2020 normals)

Typical last frost May 11 (3 days earlier than the 30-year normal), typical first fall frost September 28 (2 days later). Frost-free season 138 days.

A shorter, more recent NOAA period. The 30-year normals above remain the main reference: 15 years carry more year-to-year noise.

Add these dates to your calendar Yearly reminders for the typical last frost, the lower-risk planting date and the typical first fall frost (.ics).

How the chance of frost changes with the date

Spring at Kellogg: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 3, 20% May 26, 30% May 21, 40% May 17, 50% May 14, 60% May 11, 70% May 8, 80% May 4, 90% April 30. Observed last spring frost in recent years: 2021 May 3, 2022 May 25, 2024 May 5, 2025 May 7, 2026 April 27.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 3May 14Apr 302021: May 32022: May 252024: May 52025: May 72026: April 27Fall at Kellogg: chance of a frost before this dateFall, chance of a frost before the date: 10% September 9, 20% September 15, 30% September 19, 40% September 23, 50% September 26, 60% September 29, 70% October 2, 80% October 5, 90% October 9. Observed first fall frost in recent years: 2021 October 7, 2023 September 13, 2024 September 30, 2025 August 18.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 9Sep 26Oct 92021: October 72023: September 132024: September 302025: August 18
Two charts, because spring and fall answer different questions: in spring, the chance that a frost still comes after a date; in fall, the chance that the first frost has already come before it. NOAA publishes these odds from 10% to 90%, so the lines stop there. ◆ marks the actual date in each recent year.

What actually happened in recent years

Observed dates of the last spring and first fall frost (32°F) at this station; ◆ marks them on the charts above
YearLast spring frostFirst fall frost
2021May 3October 7
2022May 25incomplete record
2023incomplete recordSeptember 13
2024May 5September 30
2025May 7August 18
2026April 27season not over yet

What these dates mean

The 131 days between the two 32 °F 50% dates in Kellogg—from May 14 in spring to September 26 in fall—mark the interval where a light frost is as likely as not, defining the central window for tender plant growth.

In spring the cautious date for setting out tender crops is June 3, which carries only a 10 % chance of a later frost; planting earlier on April 30 entails a 90 % chance of a later frost and is a gamble. In fall the cautious date to finish harvesting tender crops is September 9, with only a 10 % chance of an earlier frost, while counting on crops through October 9 involves a 90 % chance of an earlier frost and is risky.

Hard frosts at 28 °F are more damaging than light frosts at 32 °F, so the median hard-frost dates of April 30 and October 8 signal a higher threat to plants.

How to read the probabilities

The dates are probabilities from 30 years of weather, not a forecast for this year.

  • Spring: "10% after June 3" means that in about one spring out of ten a frost still happens after that date. The 90% date is the earliest: a frost after it happens in most years.
  • Fall: "10% before September 9" means that in about one fall out of ten the first frost arrives before that date.
  • 50% is the typical date: half of the years are earlier, half are later.
  • A light frost (32°F) damages tender plants; a hard frost (28°F) also stops most hardy vegetables.

Nearby weather stations

Map of weather stations near Kellogg, IDNumbered nearest stations: 1 — Saint Maries, ID — 26 mi; 2 — near Thompson Falls, MT — 36 mi; 3 — Cabinet Gorge, ID — 38 mi; 4 — Priest River, ID — 65 mi; 5 — Spokane, WA — 66 mi.IDMTWA25 mi · 40 km1. Saint Maries, ID — 26 mi12. near Thompson Falls, MT — 36 mi23. Cabinet Gorge, ID — 38 mi34. Priest River, ID — 65 mi45. Spokane, WA — 66 mi5
  1. Saint Maries, ID 26 mi (42 km)
  2. near Thompson Falls, MT 36 mi (58 km)
  3. Cabinet Gorge, ID 38 mi (62 km)
  4. Priest River, ID 65 mi (105 km)
  5. Spokane, WA 66 mi (106 km)

Sources

* Hardiness zone 6b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 47.5339, -116.1222.