U.S. Frost Dates by Weather Station

NOAA station USC00272800 · New Hampshire

Frost Dates for Epping, NH

NOAA weather station Epping (USC00272800), New Hampshire · elevation 160 ft (49 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 21only 1 spring in 10 still has a frost later
  • Typical last frostMay 750% chance of a frost after it
  • Typical first fall frostOctober 450% chance of a frost before it
  • Frost-free season148 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Epping, NHSpring: a frost after April 25 in 9 years out of 10, after May 7 in half of the years, after May 21 in 1 year out of 10. Fall: the first frost comes before September 22 in 1 year out of 10, before October 4 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 148 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 7First frost ~Oct 4Frost season at Epping, NHSpring: a frost after April 25 in 9 years out of 10, after May 7 in half of the years, after May 21 in 1 year out of 10. Fall: the first frost comes before September 22 in 1 year out of 10, before October 4 in half of the years, before October 17 in 9 years out of 10. Typical frost-free season: 148 days.JFMAMJJASONDLast frost ~May 7First frost ~Oct 4
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 21September 22
50% (typical)May 7October 4
90% (likely)April 25October 17
Frost-free season (32°F, 50% chance)
148 days
Hard frost (28°F), last in spring, 50% chance after
April 24
Hard frost (28°F), first in fall, 50% chance before
October 15

The last 15 years (2006–2020 normals)

Typical last frost May 2 (5 days earlier than the 30-year normal), typical first fall frost October 7 (3 days later). Frost-free season 156 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 Epping: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 21, 20% May 17, 30% May 14, 40% May 10, 50% May 7, 60% May 4, 70% May 1, 80% April 29, 90% April 25. Observed last spring frost in recent years: 2021 April 27, 2022 May 9, 2023 May 18, 2024 April 27, 2025 April 22, 2026 May 9.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 21May 7Apr 252021: April 272022: May 92023: May 182024: April 272025: April 222026: May 9Fall at Epping: chance of a frost before this dateFall, chance of a frost before the date: 10% September 22, 20% September 26, 30% September 30, 40% October 1, 50% October 4, 60% October 6, 70% October 8, 80% October 12, 90% October 17. Observed first fall frost in recent years: 2021 October 24, 2022 October 9, 2023 October 31, 2024 October 15, 2025 October 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 22Oct 4Oct 172021: October 242022: October 92023: October 312024: October 152025: October 10
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 27October 24
2022May 9October 9
2023May 18October 31
2024April 27October 15
2025April 22October 10
2026May 9season not over yet

What these dates mean

Setting out tender crops on April 25 in Epping is a gamble, because there is a 90 % chance that a light frost will occur later in the season. Gardeners who wait until May 21 reduce that risk to only a 10 % chance of a frost after planting.

The 50 % dates mark the point where the odds of a light frost are even. In this location the median light-frost date in spring is May 7 and the median in fall is October 4; each represents a fifty-fifty chance of frost occurring after or before the date, respectively.

A cautious planting schedule therefore uses the May 21 date for starting tender crops in spring and the September 22 date for finishing them in fall. Hard-frost thresholds at 28 °F are more consequential because they can damage plants that survive a light frost, and the 50 % hard-frost dates are April 24 in spring and October 15 in fall.

How to read the probabilities

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

  • Spring: "10% after May 21" 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 22" 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 Epping, NHNumbered nearest stations: 1 — Durham, NH — 10 mi; 2 — Greenland, NH — 13 mi; 3 — near Manchester, NH — 16 mi; 4 — Haverhill, MA — 19 mi; 5 — Groveland, MA — 20 mi.NHMAMEVT25 mi · 40 km1. Durham, NH — 10 mi12. Greenland, NH — 13 mi23. near Manchester, NH — 16 mi34. Haverhill, MA — 19 mi45. Groveland, MA — 20 mi5
  1. Durham, NH 10 mi (17 km)
  2. Greenland, NH 13 mi (21 km)
  3. near Manchester, NH 16 mi (26 km)
  4. Haverhill, MA 19 mi (30 km)
  5. Groveland, MA 20 mi (32 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: 43.0303, -71.0839.