U.S. Frost Dates by Weather Station

NOAA station USC00283029 · New Jersey

Frost Dates for Flemington, NJ

NOAA weather station Flemington 5 NNW (USC00283029), New Jersey · elevation 265 ft (81 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 11only 1 spring in 10 still has a frost later
  • Typical last frostApril 2450% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season179 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Flemington, NJSpring: a frost after April 9 in 9 years out of 10, after April 24 in half of the years, after May 11 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 5 in 9 years out of 10. Typical frost-free season: 179 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 24First frost ~Oct 21Frost season at Flemington, NJSpring: a frost after April 9 in 9 years out of 10, after April 24 in half of the years, after May 11 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 5 in 9 years out of 10. Typical frost-free season: 179 days.JFMAMJJASONDLast frost ~Apr 24First frost ~Oct 21
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 11October 6
50% (typical)April 24October 21
90% (likely)April 9November 5
Frost-free season (32°F, 50% chance)
179 days
Hard frost (28°F), last in spring, 50% chance after
April 8
Hard frost (28°F), first in fall, 50% chance before
November 2

The last 15 years (2006–2020 normals)

Typical last frost April 20 (4 days earlier than the 30-year normal), typical first fall frost October 24 (3 days later). Frost-free season 184 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 Flemington: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 11, 20% May 5, 30% April 30, 40% April 27, 50% April 24, 60% April 21, 70% April 18, 80% April 15, 90% April 9. Observed last spring frost in recent years: 2021 April 4, 2022 May 2, 2023 April 11, 2024 April 27, 2025 April 19.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 11Apr 24Apr 92021: April 42022: May 22023: April 112024: April 272025: April 19Fall at Flemington: chance of a frost before this dateFall, chance of a frost before the date: 10% October 6, 20% October 11, 30% October 15, 40% October 18, 50% October 21, 60% October 24, 70% October 28, 80% November 1, 90% November 5. Observed first fall frost in recent years: 2021 November 4, 2022 October 19, 2023 November 2, 2024 October 17, 2025 October 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 6Oct 21Nov 52021: November 42022: October 192023: November 22024: 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 4November 4
2022May 2October 19
2023April 11November 2
2024April 27October 17
2025April 19October 10
2026incomplete recordseason not over yet

What these dates mean

The cautious fall date for finishing the tender-crop harvest in Flemington is October 6, when there is only a 10 % chance that a light frost has arrived.

For a gardener, the median 32 °F dates—April 24 in spring and October 21 in fall—mark the points at which a light frost is equally likely to have occurred or not. The median 28 °F hard-frost dates are April 8 and November 2, indicating when a hard freeze is just as likely as not. The cautious spring date for setting out tender crops is May 11, which carries a 10 % chance of a later light frost, while the early spring date of April 9 is a gamble with a 90 % chance.

A hard frost at 28 °F can damage plants that survive a light 32 °F frost, so it represents a higher risk.

How to read the probabilities

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

  • Spring: "10% after May 11" 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 October 6" 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 Flemington, NJNumbered nearest stations: 1 — New Brunswick, NJ — 25 mi; 2 — Hightstown, NJ — 27 mi; 3 — Allentown, PA — 30 mi; 4 — Newark, NJ — 38 mi; 5 — near Willingboro, NJ — 39 mi.PANY25 mi · 40 km1. New Brunswick, NJ — 25 mi12. Hightstown, NJ — 27 mi23. Allentown, PA — 30 mi34. Newark, NJ — 38 mi45. near Willingboro, NJ — 39 mi5
  1. New Brunswick, NJ 25 mi (40 km)
  2. Hightstown, NJ 27 mi (43 km)
  3. Allentown, PA 30 mi (49 km)
  4. Newark, NJ 38 mi (61 km)
  5. near Willingboro, NJ 39 mi (63 km)

Sources

* Hardiness zone 7a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 40.5739, -74.8817.