U.S. Frost Dates by Weather Station

NOAA station USC00435542 · Vermont

Frost Dates for Newport, VT

NOAA weather station Newport (USC00435542), Vermont · elevation 790 ft (241 m) · hardiness zone 4b*

  • Lower-risk planting dateafter May 28only 1 spring in 10 still has a frost later
  • Typical last frostMay 1450% chance of a frost after it
  • Typical first fall frostSeptember 3050% chance of a frost before it
  • Frost-free season138 daystypical year, 32°F
  • Hardiness zone4bcalculated*

The year at a glance

Frost season at Newport, VTSpring: a frost after May 1 in 9 years out of 10, after May 14 in half of the years, after May 28 in 1 year out of 10. Fall: the first frost comes before September 17 in 1 year out of 10, before September 30 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 138 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 14First frost ~Sep 30Frost season at Newport, VTSpring: a frost after May 1 in 9 years out of 10, after May 14 in half of the years, after May 28 in 1 year out of 10. Fall: the first frost comes before September 17 in 1 year out of 10, before September 30 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 138 days.JFMAMJJASONDLast frost ~May 14First frost ~Sep 30
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.Today

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)May 28September 17
50% (typical)May 14September 30
90% (likely)May 1October 13
Frost-free season (32°F, 50% chance)
138 days
Hard frost (28°F), last in spring, 50% chance after
May 1
Hard frost (28°F), first in fall, 50% chance before
October 10

The last 15 years (2006–2020 normals)

Typical last frost May 9 (5 days earlier than the 30-year normal), typical first fall frost October 5 (5 days later). Frost-free season 146 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 Newport: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 28, 20% May 23, 30% May 20, 40% May 16, 50% May 14, 60% May 11, 70% May 8, 80% May 5, 90% May 1. Observed last spring frost in recent years: 2021 May 8, 2022 May 9.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 28May 14May 12021: May 82022: May 9Fall at Newport: chance of a frost before this dateFall, chance of a frost before the date: 10% September 17, 20% September 22, 30% September 24, 40% September 27, 50% September 30, 60% October 2, 70% October 5, 80% October 8, 90% October 13. Observed first fall frost in recent years: 2021 October 25, 2022 October 3.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 17Sep 30Oct 132021: October 252022: October 3
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 8October 25
2022May 9October 3
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

The cautious fall date for finishing the harvest in Newport is September 17, the day that carries only a 10 % chance that a light frost has arrived earlier. For tender crops the same low-risk approach uses the spring cautious date of May 28, when there is a 10 % chance of a light frost later, while planting before May 1 would be a gamble with a 90 % chance of frost. By targeting those two dates, gardeners can plan to set out tender varieties after the spring risk has largely passed and to pull them in before the autumn risk becomes likely.

The 50 % spring date is May 14, meaning a light frost is equally likely to occur before or after that day, and the 50 % fall date is September 30, meaning a light frost is equally likely to have occurred before or after that day. Hard-frost dates at 28 °F—May 1 in spring and October 10 in fall—matter more because a hard frost can injure plants that survive a 32 °F 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 May 28" 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 September 17" 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 Newport, VTNumbered nearest stations: 1 — Island Pond, VT — 17 mi; 2 — Colebrook, NH — 32 mi; 3 — Saint Johnsbury, VT — 38 mi; 4 — near Stowe, VT — 42 mi; 5 — Lancaster, NH — 43 mi.VTNH25 mi · 40 km1. Island Pond, VT — 17 mi12. Colebrook, NH — 32 mi23. Saint Johnsbury, VT — 38 mi34. near Stowe, VT — 42 mi45. Lancaster, NH — 43 mi5
  1. Island Pond, VT 17 mi (28 km)
  2. Colebrook, NH 32 mi (52 km)
  3. Saint Johnsbury, VT 38 mi (60 km)
  4. near Stowe, VT 42 mi (68 km)
  5. Lancaster, NH 43 mi (70 km)

Sources

* Hardiness zone 4b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 44.9489, -72.1911.