U.S. Frost Dates by Weather Station

NOAA station USW00013971 · Arkansas

Frost Dates for Harrison, AR

NOAA weather station Harrison Boone County Airport (USW00013971), Arkansas · elevation 1374 ft (419 m) · hardiness zone 7b*

  • Lower-risk planting dateafter April 21only 1 spring in 10 still has a frost later
  • Typical last frostApril 350% chance of a frost after it
  • Typical first fall frostOctober 3050% chance of a frost before it
  • Frost-free season210 daystypical year, 32°F
  • Hardiness zone7bcalculated*

The year at a glance

Frost season at Harrison, ARSpring: a frost after March 17 in 9 years out of 10, after April 3 in half of the years, after April 21 in 1 year out of 10. Fall: the first frost comes before October 16 in 1 year out of 10, before October 30 in half of the years, before November 14 in 9 years out of 10. Typical frost-free season: 210 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 3First frost ~Oct 30Frost season at Harrison, ARSpring: a frost after March 17 in 9 years out of 10, after April 3 in half of the years, after April 21 in 1 year out of 10. Fall: the first frost comes before October 16 in 1 year out of 10, before October 30 in half of the years, before November 14 in 9 years out of 10. Typical frost-free season: 210 days.JFMAMJJASONDLast frost ~Apr 3First frost ~Oct 30
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)April 21October 16
50% (typical)April 3October 30
90% (likely)March 17November 14
Frost-free season (32°F, 50% chance)
210 days
Hard frost (28°F), last in spring, 50% chance after
March 24
Hard frost (28°F), first in fall, 50% chance before
November 10

The last 15 years (2006–2020 normals)

Typical last frost April 3 (same as the 30-year normal), typical first fall frost October 31 (1 day later). Frost-free season 211 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 Harrison: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 21, 20% April 14, 30% April 10, 40% April 6, 50% April 3, 60% March 31, 70% March 28, 80% March 24, 90% March 17. Observed last spring frost in recent years: 2021 April 22, 2022 April 14, 2023 April 24, 2024 March 28, 2025 April 8, 2026 March 17.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 21Apr 3Mar 172021: April 222022: April 142023: April 242024: March 282025: April 82026: March 17Fall at Harrison: chance of a frost before this dateFall, chance of a frost before the date: 10% October 16, 20% October 21, 30% October 25, 40% October 27, 50% October 30, 60% November 1, 70% November 4, 80% November 8, 90% November 14. Observed first fall frost in recent years: 2021 November 4, 2022 October 18, 2023 October 30, 2024 October 16, 2025 November 2.Fall: first frostChance of a frost before this date10%50%90%Nov 1Oct 16Oct 30Nov 142021: November 42022: October 182023: October 302024: October 162025: November 2
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 4
2022April 14October 18
2023April 24October 30
2024March 28October 16
2025April 8November 2
2026March 17season not over yet

What these dates mean

The 210 days between the 50% dates in Harrison—April 3 and October 30—mark the period in which a gardener can expect less than an even chance of a light frost and therefore plan most tender activities. Within this window the median hard-frost dates fall on March 24 and November 10, reminding that temperatures can still drop to 28 °F.

For a cautious spring plan the tender-crop date is April 21, which carries only a 10 % chance of a later frost, while planting on March 17 would be a gamble with a 90 % chance of frost. In the fall the cautious date to finish tender crops is October 16, also a 10 % chance of an earlier frost, whereas reaching November 14 would be risky. A hard frost matters more than a light frost because 28 °F can cause far greater damage to plant tissues than 32 °F.

How to read the probabilities

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

  • Spring: "10% after April 21" 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 16" 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 Harrison, ARNumbered nearest stations: 1 — Lead Hill, AR — 17 mi; 2 — Ozark Beach, MO — 28 mi; 3 — Gilbert, AR — 31 mi; 4 — Calico Rock, AR — 56 mi; 5 — Billings, MO — 59 mi.MO25 mi · 40 km1. Lead Hill, AR — 17 mi12. Ozark Beach, MO — 28 mi23. Gilbert, AR — 31 mi34. Calico Rock, AR — 56 mi45. Billings, MO — 59 mi5
  1. Lead Hill, AR 17 mi (27 km)
  2. Ozark Beach, MO 28 mi (46 km)
  3. Gilbert, AR 31 mi (50 km)
  4. Calico Rock, AR 56 mi (91 km)
  5. Billings, MO 59 mi (95 km)

Sources

* Hardiness zone 7b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 36.2667, -93.1567.