U.S. Frost Dates by Weather Station

NOAA station USC00033242 · Arkansas

Frost Dates for Helena, AR

NOAA weather station Helena (USC00033242), Arkansas · elevation 195 ft (59 m) · hardiness zone 8a*

  • Lower-risk planting dateafter April 1only 1 spring in 10 still has a frost later
  • Typical last frostMarch 1550% chance of a frost after it
  • Typical first fall frostNovember 1650% chance of a frost before it
  • Frost-free season246 daystypical year, 32°F
  • Hardiness zone8acalculated*

The year at a glance

Frost season at Helena, ARSpring: a frost after February 27 in 9 years out of 10, after March 15 in half of the years, after April 1 in 1 year out of 10. Fall: the first frost comes before November 2 in 1 year out of 10, before November 16 in half of the years, before December 4 in 9 years out of 10. Typical frost-free season: 246 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 15First frost ~Nov 16Frost season at Helena, ARSpring: a frost after February 27 in 9 years out of 10, after March 15 in half of the years, after April 1 in 1 year out of 10. Fall: the first frost comes before November 2 in 1 year out of 10, before November 16 in half of the years, before December 4 in 9 years out of 10. Typical frost-free season: 246 days.JFMAMJJASONDLast frost ~Mar 15First frost ~Nov 16
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 1November 2
50% (typical)March 15November 16
90% (likely)February 27December 4
Frost-free season (32°F, 50% chance)
246 days
Hard frost (28°F), last in spring, 50% chance after
March 3
Hard frost (28°F), first in fall, 50% chance before
November 29

The last 15 years (2006–2020 normals)

Typical last frost March 14 (1 day earlier than the 30-year normal), typical first fall frost November 15 (1 day earlier). Frost-free season 247 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 Helena: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 1, 20% March 28, 30% March 23, 40% March 18, 50% March 15, 60% March 11, 70% March 7, 80% March 3, 90% February 27. Observed last spring frost in recent years: 2024 March 20.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 1Mar 15Feb 272024: March 20Fall at Helena: chance of a frost before this dateFall, chance of a frost before the date: 10% November 2, 20% November 6, 30% November 9, 40% November 13, 50% November 16, 60% November 19, 70% November 23, 80% November 28, 90% December 4. Observed first fall frost in recent years: 2023 November 1, 2024 November 29, 2025 November 10.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Nov 2Nov 16Dec 42023: November 12024: November 292025: 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
2021incomplete recordincomplete record
2022incomplete recordincomplete record
2023incomplete recordNovember 1
2024March 20November 29
2025incomplete recordNovember 10
2026incomplete recordseason not over yet

What these dates mean

April 1 is the cautious spring date for Helena, Arkansas, carrying only a 10 % chance that a light frost will still occur later. This date lets gardeners begin setting out tender crops with relatively low risk.

Within the same climate record the 50 % light-frost dates are March 15 and November 16, marking the points where a frost is equally likely to occur later (spring) or earlier (fall). For a conservative schedule gardeners rely on the cautious fall date of November 2, which has only a 10 % chance that a frost has already arrived, to finish harvesting tender crops. The 50 % hard-frost dates are March 3 and November 29; hard frost at 28 °F can damage plants that survive a light frost, so it is a more critical threshold.

How to read the probabilities

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

  • Spring: "10% after April 1" 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 November 2" 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 Helena, ARNumbered nearest stations: 1 — Marianna, AR — 18 mi; 2 — Hernando, MS — 38 mi; 3 — Independence, MS — 45 mi; 4 — Stuttgart, AR — 47 mi; 5 — West Memphis, AR — 48 mi.ARMSTN25 mi · 40 km1. Marianna, AR — 18 mi12. Hernando, MS — 38 mi23. Independence, MS — 45 mi34. Stuttgart, AR — 47 mi45. West Memphis, AR — 48 mi5
  1. Marianna, AR 18 mi (29 km)
  2. Hernando, MS 38 mi (62 km)
  3. Independence, MS 45 mi (73 km)
  4. Stuttgart, AR 47 mi (76 km)
  5. West Memphis, AR 48 mi (77 km)

Sources

* Hardiness zone 8a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 34.5211, -90.59.