U.S. Frost Dates by Weather Station

NOAA station USC00113320 · Illinois

Frost Dates for Galesburg, IL

NOAA weather station Galesburg (USC00113320), Illinois · elevation 761 ft (232 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 5only 1 spring in 10 still has a frost later
  • Typical last frostApril 2050% chance of a frost after it
  • Typical first fall frostOctober 1950% chance of a frost before it
  • Frost-free season180 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Galesburg, ILSpring: a frost after April 6 in 9 years out of 10, after April 20 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 19 in half of the years, before October 30 in 9 years out of 10. Typical frost-free season: 180 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 20First frost ~Oct 19Frost season at Galesburg, ILSpring: a frost after April 6 in 9 years out of 10, after April 20 in half of the years, after May 5 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 19 in half of the years, before October 30 in 9 years out of 10. Typical frost-free season: 180 days.JFMAMJJASONDLast frost ~Apr 20First frost ~Oct 19
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.Today

Frost dates (32°F)

Probability of frost, based on 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 5October 4
50% (typical)April 20October 19
90% (likely)April 6October 30
Frost-free season (32°F, 50% chance)
180 days
Hard frost (28°F), last in spring, 50% chance after
April 10
Hard frost (28°F), first in fall, 50% chance before
October 28

The last 15 years (2006–2020 normals)

Typical last frost April 21 (1 day later than the 30-year normal), typical first fall frost October 20 (1 day later). Frost-free season 182 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 Galesburg: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 5, 20% April 30, 30% April 26, 40% April 22, 50% April 20, 60% April 17, 70% April 15, 80% April 11, 90% April 6. Observed last spring frost in recent years: 2021 April 23, 2022 April 27, 2023 April 24, 2024 April 22, 2025 April 9, 2026 April 21.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 5Apr 20Apr 62021: April 232022: April 272023: April 242024: April 222025: April 92026: April 21Fall at Galesburg: chance of a frost before this dateFall, chance of a frost before the date: 10% October 4, 20% October 10, 30% October 13, 40% October 16, 50% October 19, 60% October 22, 70% October 24, 80% October 27, 90% October 30. Observed first fall frost in recent years: 2021 November 1, 2022 October 8, 2023 October 30, 2024 October 16, 2025 November 2.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 4Oct 19Oct 302021: November 12022: October 82023: October 302024: October 162025: November 2
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 23November 1
2022April 27October 8
2023April 24October 30
2024April 22October 16
2025April 9November 2
2026April 21season not over yet

What these dates mean

Planting tender crops on the early spring date of April 6 in Galesburg carries a 90 % chance of a light frost, making it a gamble for growers. The cautious spring date for setting out tender crops is May 5, when only a 10 % chance of a frost later than that date remains.

The 50 % spring date of April 20 marks the point at which a light frost is equally likely to occur later, while the 50 % fall date of October 19 indicates an even chance of a frost occurring earlier. For a careful harvest schedule, the fall cautious date is October 4, offering just a 10 % chance that a frost has already arrived, whereas counting on crops surviving until October 30 is a gamble with a 90 % chance of frost earlier.

Hard frost at 28 °F is more damaging than a light frost at 32 °F, so the median hard-frost dates of April 10 and October 28 are important reference points for gardeners.

How to read the probabilities

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

  • Spring: "10% after May 5" 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 4" 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 Galesburg, ILNumbered nearest stations: 1 — Monmouth, IL — 13 mi; 2 — Galva, IL — 24 mi; 3 — Aledo, IL — 26 mi; 4 — Kewanee, IL — 33 mi; 5 — near Oquawka, IL — 34 mi.ILIA25 mi · 40 km1. Monmouth, IL — 13 mi12. Galva, IL — 24 mi23. Aledo, IL — 26 mi34. Kewanee, IL — 33 mi45. near Oquawka, IL — 34 mi5
  1. Monmouth, IL 13 mi (21 km)
  2. Galva, IL 24 mi (39 km)
  3. Aledo, IL 26 mi (41 km)
  4. Kewanee, IL 33 mi (52 km)
  5. near Oquawka, IL 34 mi (54 km)

Sources

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

Station coordinates: 40.9464, -90.3856.