U.S. Frost Dates by Weather Station

NOAA station USC00105708 · Idaho

Frost Dates for McCall, ID

NOAA weather station McCall (USC00105708), Idaho · elevation 5025 ft (1532 m) · hardiness zone 5a*

  • Lower-risk planting dateafter July 10only 1 spring in 10 still has a frost later
  • Typical last frostJune 2250% chance of a frost after it
  • Typical first fall frostSeptember 250% chance of a frost before it
  • Frost-free season72 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at McCall, IDSpring: a frost after June 3 in 9 years out of 10, after June 22 in half of the years, after July 10 in 1 year out of 10. Fall: the first frost comes before August 14 in 1 year out of 10, before September 2 in half of the years, before September 18 in 9 years out of 10. Typical frost-free season: 72 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Jun 22First frost ~Sep 2Frost season at McCall, IDSpring: a frost after June 3 in 9 years out of 10, after June 22 in half of the years, after July 10 in 1 year out of 10. Fall: the first frost comes before August 14 in 1 year out of 10, before September 2 in half of the years, before September 18 in 9 years out of 10. Typical frost-free season: 72 days.JFMAMJJASONDLast frost ~Jun 22First frost ~Sep 2
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)July 10August 14
50% (typical)June 22September 2
90% (likely)June 3September 18
Frost-free season (32°F, 50% chance)
72 days
Hard frost (28°F), last in spring, 50% chance after
June 3
Hard frost (28°F), first in fall, 50% chance before
September 15

The last 15 years (2006–2020 normals)

Typical last frost June 15 (7 days earlier than the 30-year normal), typical first fall frost September 5 (3 days later). Frost-free season 83 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 McCall: chance of a frost after this dateSpring, chance of a frost after the date: 10% July 10, 20% July 3, 30% June 29, 40% June 26, 50% June 22, 60% June 19, 70% June 15, 80% June 11, 90% June 3. Observed last spring frost in recent years: 2021 June 7, 2022 June 15, 2023 June 22, 2024 June 19, 2025 June 25, 2026 June 18.Spring: last frostChance of a frost after this date10%50%90%Jun 1Jul 1Jul 10Jun 22Jun 32021: June 72022: June 152023: June 222024: June 192025: June 252026: June 18Fall at McCall: chance of a frost before this dateFall, chance of a frost before the date: 10% August 14, 20% August 23, 30% August 28, 40% August 31, 50% September 2, 60% September 5, 70% September 8, 80% September 12, 90% September 18. Observed first fall frost in recent years: 2021 September 1, 2022 September 9, 2023 September 20, 2024 August 29, 2025 September 23.Fall: first frostChance of a frost before this date10%50%90%Aug 1Sep 1Oct 1Aug 14Sep 2Sep 182021: September 12022: September 92023: September 202024: August 292025: September 23
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
2021June 7September 1
2022June 15September 9
2023June 22September 20
2024June 19August 29
2025June 25September 23
2026June 18season not over yet

What these dates mean

The 72 days between the 50% dates in McCall frame the core frost-risk season. The 50% date is June 22, which carries a 50% chance of a light frost later than this date, and the 50% date is September 2, which carries a 50% chance of a light frost earlier than this date. Within that span the probability moves from low to high.

For a cautious planting plan, the spring light-frost date is July 10, when there is only a 10% chance of a frost later, while the fall cautious date is August 14, when there is only a 10% chance of a frost earlier. Planting or harvesting around these dates keeps the risk low.

Hard frost at 28°F, whose 50% dates are June 3 in spring and September 15 in fall, can damage or kill plants that would otherwise survive a light frost at 32°F.

How to read the probabilities

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

  • Spring: "10% after July 10" 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 August 14" 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 McCall, IDNumbered nearest stations: 1 — Cambridge, ID — 35 mi; 2 — Halfway, OR — 49 mi; 3 — Garden Valley, ID — 55 mi; 4 — Payette, ID — 69 mi; 5 — Emmett, ID — 74 mi.IDOR25 mi · 40 km1. Cambridge, ID — 35 mi12. Halfway, OR — 49 mi23. Garden Valley, ID — 55 mi34. Payette, ID — 69 mi45. Emmett, ID — 74 mi5
  1. Cambridge, ID 35 mi (57 km)
  2. Halfway, OR 49 mi (79 km)
  3. Garden Valley, ID 55 mi (88 km)
  4. Payette, ID 69 mi (111 km)
  5. Emmett, ID 74 mi (118 km)

Sources

* Hardiness zone 5a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 44.8872, -116.1047.