U.S. Frost Dates by Weather Station

NOAA station USC00116610 · Illinois

Frost Dates near Paris, IL

NOAA weather station Paris STP (USC00116610), Illinois · elevation 649 ft (198 m) · hardiness zone 6a*

Paris is the nearest town to the station (1.6 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 May 9only 1 spring in 10 still has a frost later
  • Typical last frostApril 2150% chance of a frost after it
  • Typical first fall frostOctober 2050% chance of a frost before it
  • Frost-free season179 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season near Paris, ILSpring: a frost after April 6 in 9 years out of 10, after April 21 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before October 1 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: 179 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 21First frost ~Oct 20Frost season near Paris, ILSpring: a frost after April 6 in 9 years out of 10, after April 21 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before October 1 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: 179 days.JFMAMJJASONDLast frost ~Apr 21First 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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 9October 1
50% (typical)April 21October 20
90% (likely)April 6November 1
Frost-free season (32°F, 50% chance)
179 days
Hard frost (28°F), last in spring, 50% chance after
April 9
Hard frost (28°F), first in fall, 50% chance before
October 30

The last 15 years (2006–2020 normals)

Typical last frost April 20 (1 day earlier than the 30-year normal), typical first fall frost October 22 (2 days later). Frost-free season 184 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 Paris: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 9, 20% May 1, 30% April 27, 40% April 24, 50% April 21, 60% April 18, 70% April 14, 80% April 11, 90% April 6. Observed last spring frost in recent years: 2022 April 21, 2023 April 25, 2024 April 26, 2025 April 13, 2026 April 21.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 9Apr 21Apr 62022: April 212023: April 252024: April 262025: April 132026: April 21Fall near Paris: chance of a frost before this dateFall, chance of a frost before the date: 10% October 1, 20% October 9, 30% October 14, 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 4, 2022 October 18, 2023 October 31, 2024 October 17, 2025 October 24.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 1Oct 20Nov 12021: November 42022: October 182023: October 312024: October 172025: 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
2021incomplete recordNovember 4
2022April 21October 18
2023April 25October 31
2024April 26October 17
2025April 13October 24
2026April 21season not over yet

What these dates mean

The 179 days between the 50% dates in the Paris area and what fits into them give gardeners a sense of the core growing window. The 50% light-frost dates are April 21 in spring and October 20 in fall; a gardener has a 50 % chance of a frost occurring later than April 21 and a 50 % chance of a frost occurring earlier than October 20. The 50% hard-frost dates are April 9 and October 30, marking the median points for freezes at 28 °F.

For a cautious plan, gardeners would wait until the May 9 spring date, which carries only a 10 % chance of a light frost later, before setting out tender crops. In fall, the October 1 date offers a 10 % chance of a light frost earlier and serves as the prudent cut-off for finishing tender harvests.

A hard frost at 28 °F is more damaging than a light frost at 32 °F because the lower temperature can injure plant tissue that survives the milder freeze.

How to read the probabilities

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

  • Spring: "10% after May 9" 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 1" 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 Paris, ILNumbered nearest stations: 1 — Charleston, IL — 28 mi; 2 — Perrysville, IN — 33 mi; 3 — Tuscola, IL — 35 mi; 4 — Danville, IL — 36 mi; 5 — near Jasonville, IN — 39 mi.IN25 mi · 40 km1. Charleston, IL — 28 mi12. Perrysville, IN — 33 mi23. Tuscola, IL — 35 mi34. Danville, IL — 36 mi45. near Jasonville, IN — 39 mi5
  1. Charleston, IL 28 mi (46 km)
  2. Perrysville, IN 33 mi (52 km)
  3. Tuscola, IL 35 mi (57 km)
  4. Danville, IL 36 mi (58 km)
  5. near Jasonville, IN 39 mi (63 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: 39.6186, -87.6672.