U.S. Frost Dates by Weather Station

NOAA station USC00134705 · Iowa

Frost Dates near Le Claire, IA

NOAA weather station Le Claire Lock and Dam 14 (USC00134705), Iowa · elevation 577 ft (176 m) · hardiness zone 5b*

Le Claire is the nearest town to the station (3.4 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 30only 1 spring in 10 still has a frost later
  • Typical last frostApril 1650% chance of a frost after it
  • Typical first fall frostOctober 2550% chance of a frost before it
  • Frost-free season190 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season near Le Claire, IASpring: a frost after April 2 in 9 years out of 10, after April 16 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 11 in 1 year out of 10, before October 25 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 190 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 16First frost ~Oct 25Frost season near Le Claire, IASpring: a frost after April 2 in 9 years out of 10, after April 16 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 11 in 1 year out of 10, before October 25 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 190 days.JFMAMJJASONDLast frost ~Apr 16First frost ~Oct 25
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 30October 11
50% (typical)April 16October 25
90% (likely)April 2November 6
Frost-free season (32°F, 50% chance)
190 days
Hard frost (28°F), last in spring, 50% chance after
April 6
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost April 14 (2 days earlier than the 30-year normal), typical first fall frost October 28 (3 days later). Frost-free season 194 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 Le Claire: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 30, 20% April 25, 30% April 22, 40% April 18, 50% April 16, 60% April 13, 70% April 9, 80% April 6, 90% April 2. Observed last spring frost in recent years: 2021 April 22, 2022 April 26, 2023 April 23, 2024 April 22, 2025 April 9, 2026 March 29.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 30Apr 16Apr 22021: April 222022: April 262023: April 232024: April 222025: April 92026: March 29Fall near Le Claire: chance of a frost before this dateFall, chance of a frost before the date: 10% October 11, 20% October 16, 30% October 20, 40% October 22, 50% October 25, 60% October 28, 70% October 30, 80% November 1, 90% November 6. Observed first fall frost in recent years: 2021 November 1, 2022 October 16, 2023 October 30, 2024 November 21, 2025 November 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 11Oct 25Nov 62021: November 12022: October 162023: October 302024: November 212025: November 10
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 1
2022April 26October 16
2023April 23October 30
2024April 22November 21
2025April 9November 10
2026March 29season not over yet

What these dates mean

The cautious fall date for finishing the harvest in the Le Claire area is October 11, when there is only a 10 % chance that a light frost has already arrived.

For light frosts, the 50 % dates are April 16 and October 25; April 16 represents a 50 % chance of a frost later, while October 25 represents a 50 % chance of a frost earlier. Gardeners who want to limit risk can use the cautious spring date of April 30, which carries a 10 % chance of a later frost, and the cautious fall date of October 11, which carries a 10 % chance of an earlier frost. Planting tender crops before April 30 or after October 11 would be a gamble, as the 90 %-chance dates are April 2 and November 6.

A hard frost at 28 °F is more damaging than a light frost at 32 °F, so the median hard-frost dates of April 6 and November 2 are important reference points.

How to read the probabilities

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

  • Spring: "10% after April 30" 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 11" 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 Le Claire, IANumbered nearest stations: 1 — near Rock Island, IL — 9 mi; 2 — near Moline, IL — 10 mi; 3 — Geneseo, IL — 16 mi; 4 — near Camanche, IA — 17 mi; 5 — Morrison, IL — 27 mi.ILIA25 mi · 40 km1. near Rock Island, IL — 9 mi12. near Moline, IL — 10 mi23. Geneseo, IL — 16 mi34. near Camanche, IA — 17 mi45. Morrison, IL — 27 mi5
  1. near Rock Island, IL 9 mi (15 km)
  2. near Moline, IL 10 mi (16 km)
  3. Geneseo, IL 16 mi (25 km)
  4. near Camanche, IA 17 mi (27 km)
  5. Morrison, IL 27 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: 41.5747, -90.4006.