U.S. Frost Dates by Weather Station

NOAA station USW00014923 · Illinois

Frost Dates near Moline, IL

NOAA weather station Moline Quad City International Airport (USW00014923), Illinois · elevation 592 ft (180 m) · hardiness zone 5b*

Moline is the nearest town to the station (2.9 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 2450% chance of a frost after it
  • Typical first fall frostOctober 1850% chance of a frost before it
  • Frost-free season176 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season near Moline, ILSpring: a frost after April 9 in 9 years out of 10, after April 24 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 18 in half of the years, before October 28 in 9 years out of 10. Typical frost-free season: 176 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 24First frost ~Oct 18Frost season near Moline, ILSpring: a frost after April 9 in 9 years out of 10, after April 24 in half of the years, after May 9 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 18 in half of the years, before October 28 in 9 years out of 10. Typical frost-free season: 176 days.JFMAMJJASONDLast frost ~Apr 24First frost ~Oct 18
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 9October 4
50% (typical)April 24October 18
90% (likely)April 9October 28
Frost-free season (32°F, 50% chance)
176 days
Hard frost (28°F), last in spring, 50% chance after
April 12
Hard frost (28°F), first in fall, 50% chance before
October 27

The last 15 years (2006–2020 normals)

Typical last frost April 24 (same as the 30-year normal), typical first fall frost October 19 (1 day later). Frost-free season 180 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 Moline: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 9, 20% May 4, 30% April 30, 40% April 27, 50% April 24, 60% April 21, 70% April 18, 80% April 14, 90% April 9. Observed last spring frost in recent years: 2021 May 8, 2022 April 27, 2023 April 26, 2024 April 21, 2025 April 16, 2026 May 7.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 9Apr 24Apr 92021: May 82022: April 272023: April 262024: April 212025: April 162026: May 7Fall near Moline: chance of a frost before this dateFall, chance of a frost before the date: 10% October 4, 20% October 9, 30% October 13, 40% October 16, 50% October 18, 60% October 20, 70% October 22, 80% October 25, 90% October 28. Observed first fall frost in recent years: 2021 October 23, 2022 October 14, 2023 October 30, 2024 October 15, 2025 October 23.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 4Oct 18Oct 282021: October 232022: October 142023: October 302024: October 152025: 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
2021May 8October 23
2022April 27October 14
2023April 26October 30
2024April 21October 15
2025April 16October 23
2026May 7season not over yet

What these dates mean

October 4 marks the cautious fall date for the Moline area, with only a 10 % chance that a light frost has arrived, making it the reference point for finishing the harvest of tender crops. The 50 % light-frost date is October 18; at that point there is an even chance of a light frost occurring earlier.

In spring the cautious date for setting out tender crops is May 9, when the probability of a later light frost drops to 10 %. The 50 % light-frost date is April 24, indicating a 50 % chance of a light frost later than that date. The 50 % hard-frost dates are April 12 and October 27, representing the median timing for a 28 °F frost. A hard frost matters more than a light frost because the lower temperature can damage plant tissue that would survive the milder 32 °F event.

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 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 Moline, ILNumbered nearest stations: 1 — near Rock Island, IL — 4 mi; 2 — near Le Claire, IA — 10 mi; 3 — Geneseo, IL — 19 mi; 4 — Aledo, IL — 22 mi; 5 — near Camanche, IA — 26 mi.ILIA25 mi · 40 km1. near Rock Island, IL — 4 mi12. near Le Claire, IA — 10 mi23. Geneseo, IL — 19 mi34. Aledo, IL — 22 mi45. near Camanche, IA — 26 mi5
  1. near Rock Island, IL 4 mi (7 km)
  2. near Le Claire, IA 10 mi (16 km)
  3. Geneseo, IL 19 mi (31 km)
  4. Aledo, IL 22 mi (35 km)
  5. near Camanche, IA 26 mi (43 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: 41.4653, -90.5233.