U.S. Frost Dates by Weather Station

NOAA station USC00436893 · Vermont

Frost Dates for Rochester, VT

NOAA weather station Rochester (USC00436893), Vermont · elevation 830 ft (253 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 29only 1 spring in 10 still has a frost later
  • Typical last frostMay 1350% chance of a frost after it
  • Typical first fall frostOctober 250% chance of a frost before it
  • Frost-free season141 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Rochester, VTSpring: a frost after April 30 in 9 years out of 10, after May 13 in half of the years, after May 29 in 1 year out of 10. Fall: the first frost comes before September 19 in 1 year out of 10, before October 2 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 141 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 13First frost ~Oct 2Frost season at Rochester, VTSpring: a frost after April 30 in 9 years out of 10, after May 13 in half of the years, after May 29 in 1 year out of 10. Fall: the first frost comes before September 19 in 1 year out of 10, before October 2 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 141 days.JFMAMJJASONDLast frost ~May 13First frost ~Oct 2
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 29September 19
50% (typical)May 13October 2
90% (likely)April 30October 17
Frost-free season (32°F, 50% chance)
141 days
Hard frost (28°F), last in spring, 50% chance after
April 30
Hard frost (28°F), first in fall, 50% chance before
October 13

The last 15 years (2006–2020 normals)

Typical last frost May 10 (3 days earlier than the 30-year normal), typical first fall frost October 8 (6 days later). Frost-free season 147 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 Rochester: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 29, 20% May 24, 30% May 21, 40% May 17, 50% May 13, 60% May 10, 70% May 7, 80% May 3, 90% April 30.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 29May 13Apr 30Fall at Rochester: chance of a frost before this dateFall, chance of a frost before the date: 10% September 19, 20% September 25, 30% September 29, 40% October 1, 50% October 2, 60% October 4, 70% October 7, 80% October 11, 90% October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 19Oct 2Oct 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.

What these dates mean

Setting out tender crops on April 30 in Rochester is a gamble, because there is a 90% chance of a light frost later in the season. The cautious spring date for planting tender crops is May 29, when only a 10% chance of a later frost remains. In the fall, the cautious date to finish harvesting tender crops is September 19, with just a 10% chance that a frost has already arrived, while October 17 would be a gamble with a 90% chance of an earlier frost.

The 50% dates provide a median reference: May 13 and October 2 are the 32°F 50% dates, meaning there is an even odds chance of a light frost occurring on either side of those days. April 30 and October 13 are the 28°F 50% dates, indicating a 50% chance of a hard frost. A hard frost matters more because temperatures at 28°F can damage plant tissue that survives 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 May 29" 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 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 Rochester, VTNumbered nearest stations: 1 — Rutland, VT — 18 mi; 2 — Cornwall, VT — 21 mi; 3 — near Barre, VT — 26 mi; 4 — Hanover, NH — 28 mi; 5 — Burlington, VT — 46 mi.NYNH25 mi · 40 km1. Rutland, VT — 18 mi12. Cornwall, VT — 21 mi23. near Barre, VT — 26 mi34. Hanover, NH — 28 mi45. Burlington, VT — 46 mi5
  1. Rutland, VT 18 mi (29 km)
  2. Cornwall, VT 21 mi (34 km)
  3. near Barre, VT 26 mi (42 km)
  4. Hanover, NH 28 mi (45 km)
  5. Burlington, VT 46 mi (73 km)

Sources

* Hardiness zone 5a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 43.8578, -72.8045.