NOAA station USC00114198 · Illinois
Frost Dates for Hoopeston, IL
NOAA weather station Hoopeston (USC00114198), Illinois · elevation 710 ft (216 m) · hardiness zone 6a*
- Lower-risk planting dateafter May 8only 1 spring in 10 still has a frost later
- Typical last frostApril 2250% 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 zone6acalculated*
The year at a glance
Frost dates (32°F)
| Chance | Last frost in spring after | First frost in fall before |
|---|---|---|
| 10% (unlikely) | May 8 | October 5 |
| 50% (typical) | April 22 | October 19 |
| 90% (likely) | April 7 | November 1 |
- 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 31
The last 15 years (2006–2020 normals)
Typical last frost April 23 (1 day later than the 30-year normal), typical first fall frost October 22 (3 days later). Frost-free season 181 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
What actually happened in recent years
| Year | Last spring frost | First fall frost |
|---|---|---|
| 2021 | May 8 | November 1 |
| 2022 | April 27 | October 8 |
| 2023 | April 26 | October 30 |
| 2024 | April 25 | October 16 |
| 2025 | April 16 | October 23 |
| 2026 | April 20 | season not over yet |
What these dates mean
October 5 is the cautious fall date in Hoopeston for finishing the harvest, with only a 10% chance that a light frost has arrived earlier. Gardeners who wait until the 50% date of October 19 know there is an even odds of a light frost before that point.
In spring the cautious date for setting out tender crops is May 8, which carries a 10% chance of a light frost later. The 50% date of April 22 marks the point at which a light frost is equally likely, while planting on April 7 involves a 90% chance of a frost later and is a gamble.
Hard frost reaches 28 °F, a temperature that can damage plant tissue more severely than the 32 °F of light frost; the 50% hard-frost dates are April 10 in spring and October 31 in fall.
How to read the probabilities
The dates are probabilities from 30 years of weather, not a forecast for this year.
- Spring: "10% after May 8" 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
- Danville, IL 23 mi (37 km)
- Watseka, IL 23 mi (37 km)
- Rantoul, IL 27 mi (44 km)
- Perrysville, IN 29 mi (46 km)
- West Lafayette, IN 36 mi (59 km)
Sources
- NOAA NCEI U.S. Climate Normals 1991–2020, station USC00114198
- NOAA NCEI U.S. Climate Normals
- PRISM Group, Oregon State University — 2023 USDA Plant Hardiness Zone GIS datasets
- NOAA NCEI U.S. Climate Normals 2006–2020 (15-year normals), station USC00114198
- NOAA NCEI Global Historical Climatology Network – Daily (GHCN-Daily), observed daily minimum temperature, retrieved 2026-10-08
* 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: 40.4664, -87.685.