U.S. Frost Dates by Weather Station

NOAA station USC00193276 · Massachusetts

Frost Dates for Groveland, MA

NOAA weather station Groveland (USC00193276), Massachusetts · elevation 30 ft (9 m) · hardiness zone 6b*

  • Lower-risk planting dateafter May 17only 1 spring in 10 still has a frost later
  • Typical last frostMay 350% chance of a frost after it
  • Typical first fall frostOctober 850% chance of a frost before it
  • Frost-free season158 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season at Groveland, MASpring: a frost after April 22 in 9 years out of 10, after May 3 in half of the years, after May 17 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 8 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 158 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 3First frost ~Oct 8Frost season at Groveland, MASpring: a frost after April 22 in 9 years out of 10, after May 3 in half of the years, after May 17 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 8 in half of the years, before October 23 in 9 years out of 10. Typical frost-free season: 158 days.JFMAMJJASONDLast frost ~May 3First frost ~Oct 8
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 17September 28
50% (typical)May 3October 8
90% (likely)April 22October 23
Frost-free season (32°F, 50% chance)
158 days
Hard frost (28°F), last in spring, 50% chance after
April 21
Hard frost (28°F), first in fall, 50% chance before
October 20

The last 15 years (2006–2020 normals)

Typical last frost April 30 (3 days earlier than the 30-year normal), typical first fall frost October 12 (4 days later). Frost-free season 165 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 Groveland: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 17, 20% May 12, 30% May 8, 40% May 6, 50% May 3, 60% May 1, 70% April 29, 80% April 26, 90% April 22. Observed last spring frost in recent years: 2021 April 22, 2022 May 9, 2023 May 18, 2024 April 27, 2025 April 21, 2026 April 25.Spring: last frostChance of a frost after this date10%50%90%May 1May 17May 3Apr 222021: April 222022: May 92023: May 182024: April 272025: April 212026: April 25Fall at Groveland: chance of a frost before this dateFall, chance of a frost before the date: 10% September 28, 20% October 1, 30% October 4, 40% October 6, 50% October 8, 60% October 11, 70% October 13, 80% October 18, 90% October 23. Observed first fall frost in recent years: 2021 October 24, 2022 October 9, 2023 October 31, 2024 October 17, 2025 October 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 28Oct 8Oct 232021: October 242022: October 92023: October 312024: October 172025: 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 22October 24
2022May 9October 9
2023May 18October 31
2024April 27October 17
2025April 21October 10
2026April 25season not over yet

What these dates mean

May 17 marks the cautious spring date, with only a 10 % chance of a light frost later, so gardeners can plan to set out tender crops after that day. The earlier May 3 date represents a 50 % chance of a light frost, meaning the odds are even, while the April 22 date carries a 90 % chance and would be a gamble for tender plants.

For the fall season, September 28 is the cautious date, offering a 10 % chance that a light frost has already arrived and allowing growers to finish harvesting tender crops by then. The October 8 date is the 50 % median for a light frost, and October 23 carries a 90 % chance, making later planting risky. The hard-frost median dates are April 21 in spring and October 20 in fall; a hard frost at 28 °F can damage or kill plants that would survive a light frost at 32 °F.

How to read the probabilities

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

  • Spring: "10% after May 17" 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 28" 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 Groveland, MANumbered nearest stations: 1 — Haverhill, MA — 1 mi; 2 — Lawrence, MA — 7 mi; 3 — Middleton, MA — 11 mi; 4 — Reading, MA — 16 mi; 5 — Lowell, MA — 18 mi.MANHVTME25 mi · 40 km1. Haverhill, MA — 1 mi12. Lawrence, MA — 7 mi23. Middleton, MA — 11 mi34. Reading, MA — 16 mi45. Lowell, MA — 18 mi5
  1. Haverhill, MA 1 mi (2 km)
  2. Lawrence, MA 7 mi (11 km)
  3. Middleton, MA 11 mi (17 km)
  4. Reading, MA 16 mi (26 km)
  5. Lowell, MA 18 mi (29 km)

Sources

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

Station coordinates: 42.7467, -71.0425.