U.S. Frost Dates by Weather Station

NOAA station USC00319440 · North Carolina

Frost Dates for Williamston, NC

NOAA weather station Williamston 1 E (USC00319440), North Carolina · elevation 20 ft (6 m) · hardiness zone 8b*

  • Lower-risk planting dateafter April 5only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2050% chance of a frost after it
  • Typical first fall frostNovember 1250% chance of a frost before it
  • Frost-free season239 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season at Williamston, NCSpring: a frost after March 1 in 9 years out of 10, after March 20 in half of the years, after April 5 in 1 year out of 10. Fall: the first frost comes before October 31 in 1 year out of 10, before November 12 in half of the years, before December 4 in 9 years out of 10. Typical frost-free season: 239 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 20First frost ~Nov 12Frost season at Williamston, NCSpring: a frost after March 1 in 9 years out of 10, after March 20 in half of the years, after April 5 in 1 year out of 10. Fall: the first frost comes before October 31 in 1 year out of 10, before November 12 in half of the years, before December 4 in 9 years out of 10. Typical frost-free season: 239 days.JFMAMJJASONDLast frost ~Mar 20First frost ~Nov 12
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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 5October 31
50% (typical)March 20November 12
90% (likely)March 1December 4
Frost-free season (32°F, 50% chance)
239 days
Hard frost (28°F), last in spring, 50% chance after
March 5
Hard frost (28°F), first in fall, 50% chance before
November 26

The last 15 years (2006–2020 normals)

Typical last frost March 19 (1 day earlier than the 30-year normal), typical first fall frost November 13 (1 day later). 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 Williamston: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 5, 20% March 31, 30% March 28, 40% March 24, 50% March 20, 60% March 17, 70% March 13, 80% March 7, 90% March 1. Observed last spring frost in recent years: 2021 March 8, 2022 March 30, 2023 March 22, 2024 February 22, 2025 March 3, 2026 March 29.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 5Mar 20Mar 12021: March 82022: March 302023: March 222024: February 222025: March 32026: March 29Fall at Williamston: chance of a frost before this dateFall, chance of a frost before the date: 10% October 31, 20% November 3, 30% November 6, 40% November 9, 50% November 12, 60% November 15, 70% November 19, 80% November 25, 90% December 4. Observed first fall frost in recent years: 2021 November 16, 2022 November 18, 2023 November 2, 2024 November 30, 2025 November 11.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 31Nov 12Dec 42021: November 162022: November 182023: November 22024: November 302025: November 11
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 8November 16
2022March 30November 18
2023March 22November 2
2024February 22November 30
2025March 3November 11
2026March 29season not over yet

What these dates mean

Setting out tender crops on the early spring date of March 1 is a gamble; there is a 90 % chance of a light frost after this date in Williamston. The cautious alternative is the later April 5 date, which carries only a 10 % chance of a frost later than that day.

For a gardener, the 50 % light-frost date of March 20 means there is an even odds chance of a frost later than that date, while the 50 % light-frost date of November 12 marks the point at which a frost is equally likely to have arrived earlier. The prudent planting window uses the April 5 date for tender spring crops and the October 31 date for finishing tender fall crops, each with only a 10 % chance of a frost before or after them, respectively.

Hard frost, recorded at 28 °F, is more damaging because it can kill tender plants that survive a light frost at 32 °F; the 50 % hard-frost dates are March 5 in spring and November 26 in fall.

How to read the probabilities

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

  • Spring: "10% after April 5" 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 31" 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 Williamston, NCNumbered nearest stations: 1 — Plymouth, NC — 21 mi; 2 — Greenville, NC — 25 mi; 3 — Tarboro, NC — 29 mi; 4 — Edenton, NC — 29 mi; 5 — Bayboro, NC — 51 mi.25 mi · 40 km1. Plymouth, NC — 21 mi12. Greenville, NC — 25 mi23. Tarboro, NC — 29 mi34. Edenton, NC — 29 mi45. Bayboro, NC — 51 mi5
  1. Plymouth, NC 21 mi (34 km)
  2. Greenville, NC 25 mi (41 km)
  3. Tarboro, NC 29 mi (46 km)
  4. Edenton, NC 29 mi (47 km)
  5. Bayboro, NC 51 mi (83 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: 35.8528, -77.0306.