U.S. Frost Dates by Weather Station

NOAA station USC00275211 · New Hampshire

Frost Dates near Manchester, NH

NOAA weather station Massabesic Lake (USC00275211), New Hampshire · elevation 253 ft (77 m) · hardiness zone 6a*

Manchester is the nearest town to the station (3.2 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 14only 1 spring in 10 still has a frost later
  • Typical last frostApril 3050% chance of a frost after it
  • Typical first fall frostOctober 1150% chance of a frost before it
  • Frost-free season164 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season near Manchester, NHSpring: a frost after April 19 in 9 years out of 10, after April 30 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 11 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 164 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 30First frost ~Oct 11Frost season near Manchester, NHSpring: a frost after April 19 in 9 years out of 10, after April 30 in half of the years, after May 14 in 1 year out of 10. Fall: the first frost comes before September 30 in 1 year out of 10, before October 11 in half of the years, before October 27 in 9 years out of 10. Typical frost-free season: 164 days.JFMAMJJASONDLast frost ~Apr 30First frost ~Oct 11
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 14September 30
50% (typical)April 30October 11
90% (likely)April 19October 27
Frost-free season (32°F, 50% chance)
164 days
Hard frost (28°F), last in spring, 50% chance after
April 17
Hard frost (28°F), first in fall, 50% chance before
October 24

The last 15 years (2006–2020 normals)

Typical last frost April 27 (3 days earlier than the 30-year normal), typical first fall frost October 19 (8 days later). Frost-free season 175 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 Manchester: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 14, 20% May 8, 30% May 4, 40% May 2, 50% April 30, 60% April 28, 70% April 25, 80% April 22, 90% April 19. Observed last spring frost in recent years: 2021 April 24, 2023 May 18, 2024 April 27, 2025 April 18, 2026 April 25.Spring: last frostChance of a frost after this date10%50%90%May 1May 14Apr 30Apr 192021: April 242023: May 182024: April 272025: April 182026: April 25Fall near Manchester: chance of a frost before this dateFall, chance of a frost before the date: 10% September 30, 20% October 3, 30% October 6, 40% October 8, 50% October 11, 60% October 14, 70% October 17, 80% October 22, 90% October 27. Observed first fall frost in recent years: 2021 October 29, 2022 October 9, 2023 October 31, 2024 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 30Oct 11Oct 272021: October 292022: October 92023: October 312024: 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
2021April 24October 29
2022incomplete recordOctober 9
2023May 18October 31
2024April 27October 17
2025April 18incomplete record
2026April 25season not over yet

What these dates mean

May 14 marks the cautious spring light-frost date for the Manchester area; a gardener can plan to set out tender crops after this point with only a 10 % chance of a later frost. By contrast, the 90 % chance date of April 19 would be a gamble for those same crops.

The 50 % light-frost dates are April 30 in spring and October 11 in fall, each representing an even chance of frost on either side of the date. The corresponding 50 % hard-frost dates are April 17 and October 24, indicating when a 28 °F frost is as likely as not.

September 30 is the cautious fall light-frost date, allowing a gardener to finish harvesting tender crops before the odds rise sharply. A hard frost at 28 °F can damage plant tissue more severely than a light frost at 32 °F, so it is a more critical threshold for growers.

How to read the probabilities

The dates are probabilities from 30 years of weather, not a forecast for this year.

  • Spring: "10% after May 14" 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 30" 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 Manchester, NHNumbered nearest stations: 1 — Nashua, NH — 14 mi; 2 — Concord, NH — 15 mi; 3 — Epping, NH — 16 mi; 4 — Lawrence, MA — 23 mi; 5 — Haverhill, MA — 23 mi.MAVTME25 mi · 40 km1. Nashua, NH — 14 mi12. Concord, NH — 15 mi23. Epping, NH — 16 mi34. Lawrence, MA — 23 mi45. Haverhill, MA — 23 mi5
  1. Nashua, NH 14 mi (23 km)
  2. Concord, NH 15 mi (25 km)
  3. Epping, NH 16 mi (26 km)
  4. Lawrence, MA 23 mi (37 km)
  5. Haverhill, MA 23 mi (37 km)

Sources

* Hardiness zone 6a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 42.9892, -71.3933.