U.S. Frost Dates by Weather Station

NOAA station USW00003841 · Tennessee

Frost Dates near Oak Ridge, TN

NOAA weather station Oak Ridge Atdd (USW00003841), Tennessee · elevation 905 ft (276 m) · hardiness zone 7b*

Oak Ridge is the nearest town to the station (1.3 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • Lower-risk planting dateafter April 19only 1 spring in 10 still has a frost later
  • Typical last frostApril 550% chance of a frost after it
  • Typical first fall frostNovember 150% chance of a frost before it
  • Frost-free season210 daystypical year, 32°F
  • Hardiness zone7bcalculated*

The year at a glance

Frost season near Oak Ridge, TNSpring: a frost after March 19 in 9 years out of 10, after April 5 in half of the years, after April 19 in 1 year out of 10. Fall: the first frost comes before October 19 in 1 year out of 10, before November 1 in half of the years, before November 13 in 9 years out of 10. Typical frost-free season: 210 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 5First frost ~Nov 1Frost season near Oak Ridge, TNSpring: a frost after March 19 in 9 years out of 10, after April 5 in half of the years, after April 19 in 1 year out of 10. Fall: the first frost comes before October 19 in 1 year out of 10, before November 1 in half of the years, before November 13 in 9 years out of 10. Typical frost-free season: 210 days.JFMAMJJASONDLast frost ~Apr 5First 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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 19October 19
50% (typical)April 5November 1
90% (likely)March 19November 13
Frost-free season (32°F, 50% chance)
210 days
Hard frost (28°F), last in spring, 50% chance after
March 23
Hard frost (28°F), first in fall, 50% chance before
November 11

The last 15 years (2006–2020 normals)

Typical last frost April 5 (same as the 30-year normal), typical first fall frost November 2 (1 day later). Frost-free season 212 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 near Oak Ridge: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 19, 20% April 15, 30% April 11, 40% April 8, 50% April 5, 60% April 2, 70% March 29, 80% March 25, 90% March 19. Observed last spring frost in recent years: 2021 April 22, 2022 April 10, 2023 March 20, 2024 March 19.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 19Apr 5Mar 192021: April 222022: April 102023: March 202024: March 19Fall near Oak Ridge: chance of a frost before this dateFall, chance of a frost before the date: 10% October 19, 20% October 24, 30% October 27, 40% October 30, 50% November 1, 60% November 3, 70% November 5, 80% November 8, 90% November 13. Observed first fall frost in recent years: 2021 November 6, 2022 October 18, 2023 November 1, 2024 October 17.Fall: first frostChance of a frost before this date10%50%90%Nov 1Oct 19Nov 1Nov 132021: November 62022: October 182023: November 12024: October 17
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 6
2022April 10October 18
2023March 20November 1
2024March 19October 17
2025incomplete recordno data
2026incomplete recordseason not over yet

What these dates mean

The 210 days between the 32°F 50% dates in the Oak Ridge area define the span where light-frost risk is balanced; the median spring date is April 5 and the median fall date is November 1. Within that interval, gardeners can plan most tender-crop activities, while the hard-frost 50% dates of March 23 and November 11 mark the points where a 28 °F freeze is equally likely.

The cautious spring date for setting out tender crops is April 19, which carries only a 10 % chance of a later frost, whereas planting on March 19 is a gamble with a 90 % chance. In the fall, the cautious date to finish harvesting tender crops is October 19, also with a 10 % chance of an earlier frost, while staying out until November 13 is risky with a 90 % chance. A 50% date marks the point where the odds of a light frost are equal, and a hard frost at 28 °F can damage plants that survive a light 32 °F frost.

How to read the probabilities

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

  • Spring: "10% after April 19" 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 19" 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 Oak Ridge, TNNumbered nearest stations: 1 — Lenoir City, TN — 15 mi; 2 — near Knoxville, TN — 18 mi; 3 — Norris, TN — 18 mi; 4 — Knoxville (McGhee Tyson Airport), TN — 19 mi; 5 — Sevierville, TN — 37 mi.TNNCKYVA25 mi · 40 km1. Lenoir City, TN — 15 mi12. near Knoxville, TN — 18 mi23. Norris, TN — 18 mi34. Knoxville (McGhee Tyson Airport), TN — 19 mi45. Sevierville, TN — 37 mi5
  1. Lenoir City, TN 15 mi (24 km)
  2. near Knoxville, TN 18 mi (29 km)
  3. Norris, TN 18 mi (29 km)
  4. Knoxville (McGhee Tyson Airport), TN 19 mi (31 km)
  5. Sevierville, TN 37 mi (59 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: 36.0028, -84.2486.