U.S. Frost Dates by Weather Station

NOAA station USC00275868 · New Hampshire

Frost Dates for Newport, NH

NOAA weather station Newport (USC00275868), New Hampshire · elevation 770 ft (235 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 29only 1 spring in 10 still has a frost later
  • Typical last frostMay 1450% chance of a frost after it
  • Typical first fall frostOctober 150% chance of a frost before it
  • Frost-free season140 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Newport, NHSpring: a frost after April 30 in 9 years out of 10, after May 14 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 1 in half of the years, before October 12 in 9 years out of 10. Typical frost-free season: 140 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 14First frost ~Oct 1Frost season at Newport, NHSpring: a frost after April 30 in 9 years out of 10, after May 14 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 1 in half of the years, before October 12 in 9 years out of 10. Typical frost-free season: 140 days.JFMAMJJASONDLast frost ~May 14First frost ~Oct 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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 29September 19
50% (typical)May 14October 1
90% (likely)April 30October 12
Frost-free season (32°F, 50% chance)
140 days
Hard frost (28°F), last in spring, 50% chance after
May 1
Hard frost (28°F), first in fall, 50% chance before
October 11

The last 15 years (2006–2020 normals)

Typical last frost May 12 (2 days earlier than the 30-year normal), typical first fall frost October 4 (3 days later). Frost-free season 144 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 29, 20% May 23, 30% May 20, 40% May 17, 50% May 14, 60% May 10, 70% May 7, 80% May 4, 90% April 30. Observed last spring frost in recent years: 2021 May 8, 2022 May 12, 2023 May 26, 2024 April 28, 2026 May 22.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 29May 14Apr 302021: May 82022: May 122023: May 262024: April 282026: May 22Fall at Newport: chance of a frost before this dateFall, chance of a frost before the date: 10% September 19, 20% September 24, 30% September 27, 40% September 30, 50% October 1, 60% October 3, 70% October 5, 80% October 8, 90% October 12. Observed first fall frost in recent years: 2021 October 24, 2022 September 30, 2023 October 24, 2024 October 10, 2025 September 21.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 19Oct 1Oct 122021: October 242022: September 302023: October 242024: October 102025: September 21
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 24
2022May 12September 30
2023May 26October 24
2024April 28October 10
2025incomplete recordSeptember 21
2026May 22season not over yet

What these dates mean

May 29 is the cautious spring date for Newport, New Hampshire; it gives gardeners a chance to set out tender crops with only a 10 % chance that a light frost will follow later in the season. This date marks the point at which the risk of a 32 °F frost becomes low enough to move seedlings or transplants outdoors without the higher gamble that earlier plantings entail.

The 50 % light-frost dates—May 14 in spring and October 1 in fall—indicate the median moment when a light frost is equally likely to have occurred or not, so they are useful reference points but not frost thresholds. For the autumn window, the cautious date to finish harvesting tender crops is September 19, when there is only a 10 % chance that a light frost has already arrived. The median hard-frost dates are May 1 and October 11; a hard frost at 28 °F can injure or kill many plants that survive a light frost, making it the more critical temperature limit.

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 Newport, NHNumbered nearest stations: 1 — Hanover, NH — 23 mi; 2 — Keene, NH — 31 mi; 3 — Concord, NH — 36 mi; 4 — Rutland, VT — 43 mi; 5 — Rochester, VT — 46 mi.NHNYMEMA25 mi · 40 km1. Hanover, NH — 23 mi12. Keene, NH — 31 mi23. Concord, NH — 36 mi34. Rutland, VT — 43 mi45. Rochester, VT — 46 mi5
  1. Hanover, NH 23 mi (37 km)
  2. Keene, NH 31 mi (50 km)
  3. Concord, NH 36 mi (59 km)
  4. Rutland, VT 43 mi (70 km)
  5. Rochester, 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: 43.3772, -72.1811.