U.S. Frost Dates by Weather Station

NOAA station USC00118684 · Illinois

Frost Dates for Tuscola, IL

NOAA weather station Tuscola (USC00118684), Illinois · elevation 651 ft (198 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 1only 1 spring in 10 still has a frost later
  • Typical last frostApril 1550% chance of a frost after it
  • Typical first fall frostOctober 2050% chance of a frost before it
  • Frost-free season188 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Tuscola, ILSpring: a frost after April 3 in 9 years out of 10, after April 15 in half of the years, after May 1 in 1 year out of 10. Fall: the first frost comes before October 7 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: 188 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 15First frost ~Oct 20Frost season at Tuscola, ILSpring: a frost after April 3 in 9 years out of 10, after April 15 in half of the years, after May 1 in 1 year out of 10. Fall: the first frost comes before October 7 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: 188 days.JFMAMJJASONDLast frost ~Apr 15First 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 25 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 1October 7
50% (typical)April 15October 20
90% (likely)April 3November 1
Frost-free season (32°F, 50% chance)
188 days
Hard frost (28°F), last in spring, 50% chance after
April 3
Hard frost (28°F), first in fall, 50% chance before
October 31

The last 15 years (2006–2020 normals)

Typical last frost April 14 (1 day earlier than the 30-year normal), typical first fall frost October 25 (5 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 Tuscola: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 1, 20% April 25, 30% April 21, 40% April 18, 50% April 15, 60% April 12, 70% April 10, 80% April 6, 90% April 3. Observed last spring frost in recent years: 2021 April 22, 2022 April 20, 2023 April 24, 2024 April 7, 2025 April 12, 2026 March 29.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 1Apr 15Apr 32021: April 222022: April 202023: April 242024: April 72025: April 122026: March 29Fall at Tuscola: chance of a frost before this dateFall, chance of a frost before the date: 10% October 7, 20% October 12, 30% October 15, 40% October 18, 50% October 20, 60% October 23, 70% October 25, 80% October 28, 90% November 1. Observed first fall frost in recent years: 2021 November 4, 2022 October 8, 2023 October 31, 2024 October 16, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 7Oct 20Nov 12021: November 42022: October 82023: October 312024: October 162025: 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 4
2022April 20October 8
2023April 24October 31
2024April 7October 16
2025April 12October 24
2026March 29season not over yet

What these dates mean

May 1 is the cautious spring date for setting out tender crops in Tuscola, offering a 10% chance of a light frost later and allowing gardeners to plan planting with minimal risk. The 50% date, April 15, marks the point where a light frost is equally likely to have occurred or not, while the hard-frost 50% date, April 3, indicates an even chance of temperatures reaching 28 °F.

In the fall, October 7 is the cautious date to finish harvesting tender crops, carrying only a 10% chance that a light frost has arrived earlier. The 50% light-frost date, October 20, signals even odds of a frost, and the hard-frost 50% date, October 31, shows an even chance of a 28 °F event. November 1 is a gamble with a 90% chance of a light frost. A hard frost at 28 °F can damage 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 May 1" 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 7" 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 Tuscola, ILNumbered nearest stations: 1 — Champaign, IL — 20 mi; 2 — Charleston, IL — 23 mi; 3 — Windsor, IL — 29 mi; 4 — near Paris, IL — 35 mi; 5 — Rantoul, IL — 36 mi.ILIN25 mi · 40 km1. Champaign, IL — 20 mi12. Charleston, IL — 23 mi23. Windsor, IL — 29 mi34. near Paris, IL — 35 mi45. Rantoul, IL — 36 mi5
  1. Champaign, IL 20 mi (32 km)
  2. Charleston, IL 23 mi (37 km)
  3. Windsor, IL 29 mi (47 km)
  4. near Paris, IL 35 mi (57 km)
  5. Rantoul, IL 36 mi (59 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: 39.7947, -88.2911.