U.S. Frost Dates by Weather Station

NOAA station USW00093822 · Illinois

Frost Dates near Springfield, IL

NOAA weather station Springfield Capital Airport (USW00093822), Illinois · elevation 594 ft (181 m) · hardiness zone 6a*

Springfield is the nearest town to the station (3.7 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter April 29only 1 spring in 10 still has a frost later
  • Typical last frostApril 1450% chance of a frost after it
  • Typical first fall frostOctober 2050% chance of a frost before it
  • Frost-free season187 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season near Springfield, ILSpring: a frost after April 1 in 9 years out of 10, after April 14 in half of the years, after April 29 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 20 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 187 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 14First frost ~Oct 20Frost season near Springfield, ILSpring: a frost after April 1 in 9 years out of 10, after April 14 in half of the years, after April 29 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 20 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 187 days.JFMAMJJASONDLast frost ~Apr 14First frost ~Oct 20
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 29October 5
50% (typical)April 14October 20
90% (likely)April 1November 1
Frost-free season (32°F, 50% chance)
187 days
Hard frost (28°F), last in spring, 50% chance after
April 3
Hard frost (28°F), first in fall, 50% chance before
October 30

The last 15 years (2006–2020 normals)

Typical last frost April 15 (1 day later than the 30-year normal), typical first fall frost October 21 (1 day later). Frost-free season 188 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 near Springfield: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 29, 20% April 24, 30% April 20, 40% April 16, 50% April 14, 60% April 11, 70% April 8, 80% April 5, 90% April 1. Observed last spring frost in recent years: 2021 April 22, 2022 April 19, 2023 April 24, 2024 April 21, 2025 April 8, 2026 April 20.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 29Apr 14Apr 12021: April 222022: April 192023: April 242024: April 212025: April 82026: April 20Fall near Springfield: chance of a frost before this dateFall, chance of a frost before the date: 10% October 5, 20% October 11, 30% October 15, 40% October 17, 50% October 20, 60% October 22, 70% October 25, 80% October 28, 90% November 1. Observed first fall frost in recent years: 2021 November 2, 2022 October 8, 2023 October 30, 2024 October 16, 2025 October 23.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 5Oct 20Nov 12021: November 22022: October 82023: October 302024: October 162025: October 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
2021April 22November 2
2022April 19October 8
2023April 24October 30
2024April 21October 16
2025April 8October 23
2026April 20season not over yet

What these dates mean

The 187 days between the 32°F 50% dates in the Springfield area frame the window for tender crops. The 50% date is April 14, when there is an even chance a light frost will occur later, and the 50% date is October 20, when there is an even chance a light frost has already arrived. The median hard-frost dates are April 3 and October 30, marking the point of equal likelihood for a 28 °F freeze.

Gardeners who prefer a cautious approach would wait until the April 29 light-frost date, which carries only a 10 % chance of a later frost, before setting out tender crops, and would aim to finish those crops by the October 5 light-frost date, which likewise has only a 10 % chance that frost has arrived earlier.

A hard frost at 28 °F can damage plant tissue that often survives 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 April 29" 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 5" 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 Springfield, ILNumbered nearest stations: 1 — Lincoln, IL — 28 mi; 2 — Jacksonville, IL — 28 mi; 3 — White Hall, IL — 46 mi; 4 — Hillsboro, IL — 48 mi; 5 — Peoria, IL — 57 mi.MOIA50 mi · 80 km1. Lincoln, IL — 28 mi12. Jacksonville, IL — 28 mi23. White Hall, IL — 46 mi34. Hillsboro, IL — 48 mi45. Peoria, IL — 57 mi5
  1. Lincoln, IL 28 mi (45 km)
  2. Jacksonville, IL 28 mi (46 km)
  3. White Hall, IL 46 mi (75 km)
  4. Hillsboro, IL 48 mi (78 km)
  5. Peoria, IL 57 mi (91 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: 39.8447, -89.6839.