U.S. Frost Dates by Weather Station

NOAA station USC00031140 · Arkansas

Frost Dates for Calion Lock and Dam, AR

NOAA weather station Calion Lock and Dam (USC00031140), Arkansas · elevation 77 ft (24 m) · hardiness zone 8b*

  • Lower-risk planting dateafter April 6only 1 spring in 10 still has a frost later
  • Typical last frostMarch 1850% chance of a frost after it
  • Typical first fall frostNovember 750% chance of a frost before it
  • Frost-free season235 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season at Calion Lock and Dam, ARSpring: a frost after February 28 in 9 years out of 10, after March 18 in half of the years, after April 6 in 1 year out of 10. Fall: the first frost comes before October 24 in 1 year out of 10, before November 7 in half of the years, before November 27 in 9 years out of 10. Typical frost-free season: 235 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 18First frost ~Nov 7Frost season at Calion Lock and Dam, ARSpring: a frost after February 28 in 9 years out of 10, after March 18 in half of the years, after April 6 in 1 year out of 10. Fall: the first frost comes before October 24 in 1 year out of 10, before November 7 in half of the years, before November 27 in 9 years out of 10. Typical frost-free season: 235 days.JFMAMJJASONDLast frost ~Mar 18First frost ~Nov 7
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.Today

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 6October 24
50% (typical)March 18November 7
90% (likely)February 28November 27
Frost-free season (32°F, 50% chance)
235 days
Hard frost (28°F), last in spring, 50% chance after
March 4
Hard frost (28°F), first in fall, 50% chance before
November 21

The last 15 years (2006–2020 normals)

Typical last frost March 14 (4 days earlier than the 30-year normal), typical first fall frost November 7. Frost-free season 240 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 Calion Lock and Dam: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 6, 20% April 1, 30% March 27, 40% March 22, 50% March 18, 60% March 15, 70% March 10, 80% March 6, 90% February 28. Observed last spring frost in recent years: 2021 March 4, 2022 March 14, 2023 March 21, 2024 March 20, 2025 March 22.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 6Mar 18Feb 282021: March 42022: March 142023: March 212024: March 202025: March 22Fall at Calion Lock and Dam: chance of a frost before this dateFall, chance of a frost before the date: 10% October 24, 20% October 30, 30% November 2, 40% November 5, 50% November 7, 60% November 11, 70% November 15, 80% November 19, 90% November 27. Observed first fall frost in recent years: 2021 November 5, 2022 October 19, 2023 November 2, 2024 November 23, 2025 November 10.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 24Nov 7Nov 272021: November 52022: October 192023: November 22024: November 232025: 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
2021March 4November 5
2022March 14October 19
2023March 21November 2
2024March 20November 23
2025March 22November 10
2026incomplete recordseason not over yet

What these dates mean

The 235 days between the 32 °F 50% dates, March 18 and November 7, mark the span in which tender crops can be cultivated at Calion Lock and Dam. The 50% dates themselves represent the point of even odds for a light frost, so a gardener knows that frost is equally likely to occur before or after each of those days.

In spring the cautious date for setting out tender crops is April 6, when there is only a 10 % chance of a frost later than that day; planting on February 28 carries a 90 % chance of a frost later and is a gamble. In fall the cautious date to finish harvesting tender crops is October 24, with a 10 % chance of a frost earlier than that day; waiting until November 27 involves a 90 % chance of a frost earlier and is a gamble.

A hard frost at 28 °F can injure plants that would survive a 32 °F light frost, making it a greater risk.

How to read the probabilities

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

  • Spring: "10% after April 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 24" 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 Calion Lock and Dam, ARNumbered nearest stations: 1 — near El Dorado, AR — 20 mi; 2 — Camden, AR — 28 mi; 3 — Crossett, AR — 34 mi; 4 — Fordyce, AR — 36 mi; 5 — Monticello, AR — 48 mi.ARLAMS25 mi · 40 km1. near El Dorado, AR — 20 mi12. Camden, AR — 28 mi23. Crossett, AR — 34 mi34. Fordyce, AR — 36 mi45. Monticello, AR — 48 mi5
  1. near El Dorado, AR 20 mi (32 km)
  2. Camden, AR 28 mi (45 km)
  3. Crossett, AR 34 mi (54 km)
  4. Fordyce, AR 36 mi (58 km)
  5. Monticello, AR 48 mi (77 km)

Sources

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

Station coordinates: 33.3064, -92.4833.