U.S. Frost Dates by Weather Station

NOAA station USC00405158 · Tennessee

Frost Dates for Lenoir City, TN

NOAA weather station Lenoir City (USC00405158), Tennessee · elevation 785 ft (239 m) · hardiness zone 7b*

  • Lower-risk planting dateafter April 21only 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 at Lenoir City, TNSpring: a frost after March 19 in 9 years out of 10, after April 5 in half of the years, after April 21 in 1 year out of 10. Fall: the first frost comes before October 20 in 1 year out of 10, before November 1 in half of the years, before November 15 in 9 years out of 10. Typical frost-free season: 210 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 5First frost ~Nov 1Frost season at Lenoir City, TNSpring: a frost after March 19 in 9 years out of 10, after April 5 in half of the years, after April 21 in 1 year out of 10. Fall: the first frost comes before October 20 in 1 year out of 10, before November 1 in half of the years, before November 15 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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 21October 20
50% (typical)April 5November 1
90% (likely)March 19November 15
Frost-free season (32°F, 50% chance)
210 days
Hard frost (28°F), last in spring, 50% chance after
March 25
Hard frost (28°F), first in fall, 50% chance before
November 12

The last 15 years (2006–2020 normals)

Typical last frost April 6 (1 day later than the 30-year normal), typical first fall frost November 2 (1 day later). Frost-free season 211 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 Lenoir City: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 21, 20% April 16, 30% April 12, 40% April 8, 50% April 5, 60% April 2, 70% March 30, 80% March 25, 90% March 19. Observed last spring frost in recent years: 2021 April 23, 2022 April 11, 2023 March 23, 2024 March 20, 2025 March 22, 2026 March 29.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 21Apr 5Mar 192021: April 232022: April 112023: March 232024: March 202025: March 222026: March 29Fall at Lenoir City: chance of a frost before this dateFall, chance of a frost before the date: 10% October 20, 20% October 25, 30% October 28, 40% October 31, 50% November 1, 60% November 4, 70% November 7, 80% November 10, 90% November 15. Observed first fall frost in recent years: 2021 November 6, 2022 October 20, 2023 November 1, 2024 November 30, 2025 November 10.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 20Nov 1Nov 152021: November 62022: October 202023: November 12024: November 302025: 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
2021April 23November 6
2022April 11October 20
2023March 23November 1
2024March 20November 30
2025March 22November 10
2026March 29season not over yet

What these dates mean

October 20 marks the cautious fall date for finishing the harvest of tender crops in Lenoir City; there is only a 10% chance that a light frost has arrived earlier. In spring, the cautious date for setting out tender crops is April 21, which carries a 10% chance of a frost later, while planting on March 19 would be a gamble with a 90% chance of frost later.

The 50% dates give a balanced view of frost risk. The 32°F 50% date is April 5 in spring, meaning a 50% chance of a frost later than that day, and November 1 in fall, meaning a 50% chance of a frost earlier than that day. For hard frost, the median dates are March 25 and November 12, indicating the points at which a 28°F frost is equally likely to have occurred or not. A hard frost matters more because it can damage plants that survive a light 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 21" 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 20" 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 Lenoir City, TNNumbered nearest stations: 1 — near Oak Ridge, TN — 15 mi; 2 — Knoxville (McGhee Tyson Airport), TN — 16 mi; 3 — near Knoxville, TN — 19 mi; 4 — Athens, TN — 30 mi; 5 — Norris, TN — 31 mi.TNNCKY25 mi · 40 km1. near Oak Ridge, TN — 15 mi12. Knoxville (McGhee Tyson Airport), TN — 16 mi23. near Knoxville, TN — 19 mi34. Athens, TN — 30 mi45. Norris, TN — 31 mi5
  1. near Oak Ridge, TN 15 mi (24 km)
  2. Knoxville (McGhee Tyson Airport), TN 16 mi (25 km)
  3. near Knoxville, TN 19 mi (30 km)
  4. Athens, TN 30 mi (49 km)
  5. Norris, TN 31 mi (51 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: 35.7875, -84.2622.