U.S. Frost Dates by Weather Station

NOAA station USC00406292 · Tennessee

Frost Dates near Mountain City, TN

NOAA weather station Mountain City 2 (USC00406292), Tennessee · elevation 2419 ft (737 m) · hardiness zone 7a*

Mountain City is the nearest town to the station (0.1 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 May 15only 1 spring in 10 still has a frost later
  • Typical last frostApril 2750% chance of a frost after it
  • Typical first fall frostOctober 1450% chance of a frost before it
  • Frost-free season170 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season near Mountain City, TNSpring: a frost after April 12 in 9 years out of 10, after April 27 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 14 in half of the years, before October 30 in 9 years out of 10. Typical frost-free season: 170 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 27First frost ~Oct 14Frost season near Mountain City, TNSpring: a frost after April 12 in 9 years out of 10, after April 27 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 3 in 1 year out of 10, before October 14 in half of the years, before October 30 in 9 years out of 10. Typical frost-free season: 170 days.JFMAMJJASONDLast frost ~Apr 27First frost ~Oct 14
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)May 15October 3
50% (typical)April 27October 14
90% (likely)April 12October 30
Frost-free season (32°F, 50% chance)
170 days
Hard frost (28°F), last in spring, 50% chance after
April 12
Hard frost (28°F), first in fall, 50% chance before
October 24

The last 15 years (2006–2020 normals)

Typical last frost April 26 (1 day earlier than the 30-year normal), typical first fall frost October 18 (4 days later). Frost-free season 174 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 Mountain City: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 15, 20% May 8, 30% May 4, 40% April 30, 50% April 27, 60% April 23, 70% April 20, 80% April 17, 90% April 12. Observed last spring frost in recent years: 2021 May 13, 2022 April 21, 2023 May 4, 2024 April 25.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 15Apr 27Apr 122021: May 132022: April 212023: May 42024: April 25Fall near Mountain City: chance of a frost before this dateFall, chance of a frost before the date: 10% October 3, 20% October 6, 30% October 9, 40% October 12, 50% October 14, 60% October 17, 70% October 21, 80% October 24, 90% October 30. Observed first fall frost in recent years: 2021 October 19, 2022 October 9, 2023 October 23, 2024 October 11, 2025 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 3Oct 14Oct 302021: October 192022: October 92023: October 232024: October 112025: 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
2021May 13October 19
2022April 21October 9
2023May 4October 23
2024April 25October 11
2025incomplete recordOctober 17
2026incomplete recordseason not over yet

What these dates mean

The cautious fall date for finishing the harvest in the Mountain City area is October 3, when there is only a 10 % chance that a light frost has arrived.

The 50 % date in spring, April 27, represents a 50 % chance of a light frost later than this date, while the 50 % date in fall, October 14, represents a 50 % chance of a light frost earlier than this date. For tender crops, the cautious spring date is May 15, with a 10 % chance of a later light frost, whereas the cautious fall date is October 3, with a 10 % chance of an earlier light frost.

A hard frost at 28 °F, whose median dates are April 12 in spring and October 24 in fall, is more damaging than a light frost because the lower temperature can injure plant tissue that survives the milder 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 May 15" 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 3" 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 Mountain City, TNNumbered nearest stations: 1 — Abingdon, VA — 16 mi; 2 — Boone, NC — 20 mi; 3 — near Banner Elk, NC — 20 mi; 4 — Jefferson, NC — 21 mi; 5 — Elizabethton, TN — 26 mi.VATN25 mi · 40 km1. Abingdon, VA — 16 mi12. Boone, NC — 20 mi23. near Banner Elk, NC — 20 mi34. Jefferson, NC — 21 mi45. Elizabethton, TN — 26 mi5
  1. Abingdon, VA 16 mi (26 km)
  2. Boone, NC 20 mi (32 km)
  3. near Banner Elk, NC 20 mi (32 km)
  4. Jefferson, NC 21 mi (34 km)
  5. Elizabethton, TN 26 mi (42 km)

Sources

* Hardiness zone 7a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 36.4739, -81.8033.