U.S. Frost Dates by Weather Station

NOAA station USW00014842 · Illinois

Frost Dates for Peoria, IL

NOAA weather station Peoria Greater Peoria Airport (USW00014842), Illinois · elevation 650 ft (198 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 4only 1 spring in 10 still has a frost later
  • Typical last frostApril 1650% chance of a frost after it
  • Typical first fall frostOctober 2350% chance of a frost before it
  • Frost-free season189 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Peoria, ILSpring: a frost after April 2 in 9 years out of 10, after April 16 in half of the years, after May 4 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 23 in half of the years, before November 3 in 9 years out of 10. Typical frost-free season: 189 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 16First frost ~Oct 23Frost season at Peoria, ILSpring: a frost after April 2 in 9 years out of 10, after April 16 in half of the years, after May 4 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 23 in half of the years, before November 3 in 9 years out of 10. Typical frost-free season: 189 days.JFMAMJJASONDLast frost ~Apr 16First frost ~Oct 23
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)May 4October 9
50% (typical)April 16October 23
90% (likely)April 2November 3
Frost-free season (32°F, 50% chance)
189 days
Hard frost (28°F), last in spring, 50% chance after
April 5
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost April 17 (1 day later than the 30-year normal), typical first fall frost October 25 (2 days later). Frost-free season 192 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 Peoria: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 4, 20% April 28, 30% April 23, 40% April 20, 50% April 16, 60% April 13, 70% April 10, 80% April 6, 90% April 2. Observed last spring frost in recent years: 2021 April 22, 2022 April 26, 2023 April 24, 2024 April 6, 2025 April 8, 2026 April 20.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 4Apr 16Apr 22021: April 222022: April 262023: April 242024: April 62025: April 82026: April 20Fall at Peoria: chance of a frost before this dateFall, chance of a frost before the date: 10% October 9, 20% October 15, 30% October 18, 40% October 20, 50% October 23, 60% October 25, 70% October 28, 80% October 31, 90% November 3. Observed first fall frost in recent years: 2021 November 1, 2022 October 18, 2023 October 30, 2024 November 21, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 9Oct 23Nov 32021: November 12022: October 182023: October 302024: November 212025: October 24
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
2021April 22November 1
2022April 26October 18
2023April 24October 30
2024April 6November 21
2025April 8October 24
2026April 20season not over yet

What these dates mean

In Peoria, setting out tender crops on April 2 carries a 90 % chance of a light frost later that season, making it a gamble. The cautious alternative for planting tender varieties is May 4, when the chance of a later frost drops to 10 %.

The 50 % dates—April 16 in spring and October 23 in fall—represent the point at which a light frost is equally likely to have occurred or not; they are not frost dates themselves but help gauge risk. For gardeners planning a conservative harvest schedule, the cautious fall date is October 9, which has only a 10 % chance that a light frost has already arrived, while November 3 would be a gamble with a 90 % chance of an earlier frost.

A hard frost at 28 °F, marked by the median dates April 5 and November 2, can damage plants that survive a 32 °F light frost, so it is a more severe threat.

How to read the probabilities

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

  • Spring: "10% after May 4" 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 October 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 Peoria, ILNumbered nearest stations: 1 — Minonk, IL — 38 mi; 2 — Normal, IL — 39 mi; 3 — Galva, IL — 39 mi; 4 — Lincoln, IL — 40 mi; 5 — Kewanee, IL — 41 mi.ILIA25 mi · 40 km1. Minonk, IL — 38 mi12. Normal, IL — 39 mi23. Galva, IL — 39 mi34. Lincoln, IL — 40 mi45. Kewanee, IL — 41 mi5
  1. Minonk, IL 38 mi (61 km)
  2. Normal, IL 39 mi (63 km)
  3. Galva, IL 39 mi (64 km)
  4. Lincoln, IL 40 mi (64 km)
  5. Kewanee, IL 41 mi (66 km)

Sources

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

Station coordinates: 40.6675, -89.6839.