U.S. Frost Dates by Weather Station

NOAA station USC00130536 · Iowa

Frost Dates for Beaconsfield, IA

NOAA weather station Beaconsfield (USC00130536), Iowa · elevation 1215 ft (370 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 6only 1 spring in 10 still has a frost later
  • Typical last frostApril 2350% chance of a frost after it
  • Typical first fall frostOctober 1750% chance of a frost before it
  • Frost-free season176 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Beaconsfield, IASpring: a frost after April 7 in 9 years out of 10, after April 23 in half of the years, after May 6 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 17 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 176 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 23First frost ~Oct 17Frost season at Beaconsfield, IASpring: a frost after April 7 in 9 years out of 10, after April 23 in half of the years, after May 6 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 17 in half of the years, before October 31 in 9 years out of 10. Typical frost-free season: 176 days.JFMAMJJASONDLast frost ~Apr 23First frost ~Oct 17
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 6October 1
50% (typical)April 23October 17
90% (likely)April 7October 31
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 28

The last 15 years (2006–2020 normals)

Typical last frost April 22 (1 day earlier than the 30-year normal), typical first fall frost October 20 (3 days 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 at Beaconsfield: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 6, 20% May 2, 30% April 29, 40% April 25, 50% April 23, 60% April 19, 70% April 16, 80% April 12, 90% April 7. Observed last spring frost in recent years: 2021 April 23.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 6Apr 23Apr 72021: April 23Fall at Beaconsfield: chance of a frost before this dateFall, chance of a frost before the date: 10% October 1, 20% October 6, 30% October 10, 40% October 14, 50% October 17, 60% October 20, 70% October 23, 80% October 26, 90% October 31. Observed first fall frost in recent years: 2021 October 22.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 1Oct 17Oct 312021: October 22
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 23October 22
2022no datano data
2023incomplete recordincomplete record
2024incomplete recordincomplete record
2025incomplete recordno data
2026no dataseason not over yet

What these dates mean

The cautious fall date for finishing the harvest in Beaconsfield is October 1, when there is only a 10 % chance that a light frost has arrived.

The 50 % dates are the median points for light frost risk: April 23 in spring and October 17 in fall. Each of those dates carries an even chance of a frost later (spring) or earlier (fall). The hard-frost 28 °F median dates are April 12 and October 28; a hard frost can damage plants more severely than a light frost because the lower temperature penetrates tissue more deeply.

For a cautious planting plan, tender crops are best set out after the spring cautious date of May 6, when only a 10 % chance of a later light frost remains, and harvested before the fall cautious date of October 1, when the same low risk applies.

How to read the probabilities

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

  • Spring: "10% after May 6" 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 Beaconsfield, IANumbered nearest stations: 1 — Mount Ayr, IA — 12 mi; 2 — Lamoni, IA — 14 mi; 3 — Osceola, IA — 21 mi; 4 — Creston, IA — 24 mi; 5 — Bedford, IA — 37 mi.IAMO25 mi · 40 km1. Mount Ayr, IA — 12 mi12. Lamoni, IA — 14 mi23. Osceola, IA — 21 mi34. Creston, IA — 24 mi45. Bedford, IA — 37 mi5
  1. Mount Ayr, IA 12 mi (20 km)
  2. Lamoni, IA 14 mi (23 km)
  3. Osceola, IA 21 mi (34 km)
  4. Creston, IA 24 mi (39 km)
  5. Bedford, IA 37 mi (59 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: 40.8069, -94.0475.