U.S. Frost Dates by Weather Station

NOAA station USC00030798 · Arkansas

Frost Dates for Blue Mountain Dam, AR

NOAA weather station Blue Mountain Dam (USC00030798), Arkansas · elevation 426 ft (130 m) · hardiness zone 8a*

  • Lower-risk planting dateafter April 17only 1 spring in 10 still has a frost later
  • Typical last frostMarch 3150% chance of a frost after it
  • Typical first fall frostNovember 150% chance of a frost before it
  • Frost-free season215 daystypical year, 32°F
  • Hardiness zone8acalculated*

The year at a glance

Frost season at Blue Mountain Dam, ARSpring: a frost after March 12 in 9 years out of 10, after March 31 in half of the years, after April 17 in 1 year out of 10. Fall: the first frost comes before October 18 in 1 year out of 10, before November 1 in half of the years, before November 17 in 9 years out of 10. Typical frost-free season: 215 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 31First frost ~Nov 1Frost season at Blue Mountain Dam, ARSpring: a frost after March 12 in 9 years out of 10, after March 31 in half of the years, after April 17 in 1 year out of 10. Fall: the first frost comes before October 18 in 1 year out of 10, before November 1 in half of the years, before November 17 in 9 years out of 10. Typical frost-free season: 215 days.JFMAMJJASONDLast frost ~Mar 31First frost ~Nov 1
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 17October 18
50% (typical)March 31November 1
90% (likely)March 12November 17
Frost-free season (32°F, 50% chance)
215 days
Hard frost (28°F), last in spring, 50% chance after
March 17
Hard frost (28°F), first in fall, 50% chance before
November 12

The last 15 years (2006–2020 normals)

Typical last frost March 29 (2 days earlier than the 30-year normal), typical first fall frost November 1. Frost-free season 220 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 Blue Mountain Dam: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 17, 20% April 11, 30% April 7, 40% April 3, 50% March 31, 60% March 28, 70% March 23, 80% March 18, 90% March 12. Observed last spring frost in recent years: 2021 April 3, 2022 April 14, 2023 March 21, 2024 March 28, 2025 March 24.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 17Mar 31Mar 122021: April 32022: April 142023: March 212024: March 282025: March 24Fall at Blue Mountain Dam: chance of a frost before this dateFall, chance of a frost before the date: 10% October 18, 20% October 23, 30% October 27, 40% October 30, 50% November 1, 60% November 3, 70% November 6, 80% November 11, 90% November 17. Observed first fall frost in recent years: 2021 November 5, 2023 November 1.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 18Nov 1Nov 172021: November 52023: November 1
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 3November 5
2022April 14incomplete record
2023March 21November 1
2024March 28incomplete record
2025March 24incomplete record
2026incomplete recordseason not over yet

What these dates mean

April 17 is the cautious spring light-frost date for Blue Mountain Dam, with only a 10 % chance of a frost later. That date lets a gardener schedule the final placement of tender seedlings outdoors with minimal risk of a late light frost.

The 50% dates—March 31 for spring and November 1 for fall—represent the point at which a light frost is equally likely to have occurred or not, giving a median reference for timing. For a cautious autumn plan the date to finish harvesting tender crops is October 18, which carries only a 10 % chance that a frost has already arrived. The 50% hard-frost dates are March 17 and November 12; a hard frost can damage or kill plants that survive a 32 °F light frost, so it represents a higher level of threat.

How to read the probabilities

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

  • Spring: "10% after April 17" 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 18" 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 Blue Mountain Dam, ARNumbered nearest stations: 1 — Subiaco, AR — 13 mi; 2 — Dardanelle, AR — 28 mi; 3 — near Ola, AR — 30 mi; 4 — Ozark, AR — 30 mi; 5 — Fort Smith, AR — 43 mi.OK25 mi · 40 km1. Subiaco, AR — 13 mi12. Dardanelle, AR — 28 mi23. near Ola, AR — 30 mi34. Ozark, AR — 30 mi45. Fort Smith, AR — 43 mi5
  1. Subiaco, AR 13 mi (21 km)
  2. Dardanelle, AR 28 mi (46 km)
  3. near Ola, AR 30 mi (48 km)
  4. Ozark, AR 30 mi (48 km)
  5. Fort Smith, AR 43 mi (69 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: 35.1161, -93.6506.