U.S. Frost Dates by Weather Station

NOAA station USC00364325 · Pennsylvania

Frost Dates for Jamestown, PA

NOAA weather station Jamestown 2 NW (USC00364325), Pennsylvania · elevation 1040 ft (317 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 22only 1 spring in 10 still has a frost later
  • Typical last frostMay 450% chance of a frost after it
  • Typical first fall frostOctober 1450% chance of a frost before it
  • Frost-free season161 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Jamestown, PASpring: a frost after April 22 in 9 years out of 10, after May 4 in half of the years, after May 22 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 14 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 161 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 4First frost ~Oct 14Frost season at Jamestown, PASpring: a frost after April 22 in 9 years out of 10, after May 4 in half of the years, after May 22 in 1 year out of 10. Fall: the first frost comes before October 1 in 1 year out of 10, before October 14 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 161 days.JFMAMJJASONDLast frost ~May 4First frost ~Oct 14
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 22October 1
50% (typical)May 4October 14
90% (likely)April 22November 1
Frost-free season (32°F, 50% chance)
161 days
Hard frost (28°F), last in spring, 50% chance after
April 25
Hard frost (28°F), first in fall, 50% chance before
October 30

The last 15 years (2006–2020 normals)

Typical last frost May 4 (same as the 30-year normal), typical first fall frost October 19 (5 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 Jamestown: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 22, 20% May 17, 30% May 12, 40% May 9, 50% May 4, 60% May 1, 70% April 29, 80% April 25, 90% April 22. Observed last spring frost in recent years: 2021 May 6, 2022 April 30, 2023 May 18, 2024 April 26, 2025 April 18, 2026 May 12.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 22May 4Apr 222021: May 62022: April 302023: May 182024: April 262025: April 182026: May 12Fall at Jamestown: chance of a frost before this dateFall, chance of a frost before the date: 10% October 1, 20% October 5, 30% October 8, 40% October 11, 50% October 14, 60% October 18, 70% October 21, 80% October 25, 90% November 1. Observed first fall frost in recent years: 2021 November 3, 2022 October 9, 2023 October 23, 2024 October 11, 2025 October 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 1Oct 14Nov 12021: November 32022: October 92023: October 232024: October 112025: 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
2021May 6November 3
2022April 30October 9
2023May 18October 23
2024April 26October 11
2025April 18October 17
2026May 12season not over yet

What these dates mean

The 161 days between the 50% dates in Jamestown, May 4 and October 14, bound the period when a garden can generally avoid light frosts. On each of those dates the chance of a 32 °F frost is 50%, marking the median point of the 30-year record. The 50% dates for hard frost are April 25 and October 30.

In spring, the cautious date for setting out tender crops is May 22, when there is only a 10 % chance of a light frost occurring later; planting on April 22 carries a 90 % chance and is a gamble. In fall, the cautious date to finish harvesting tender crops is October 1, with a 10 % chance of a light frost having arrived earlier, while October 14 is the median and November 1 is a 90 % gamble. A hard frost at 28 °F can damage plants more severely than 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 22" 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 1" 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 Jamestown, PANumbered nearest stations: 1 — Linesville, PA — 10 mi; 2 — Dorset, OH — 16 mi; 3 — Youngstown, OH — 20 mi; 4 — Warren, OH — 27 mi; 5 — Hiram, OH — 31 mi.PAOHNY25 mi · 40 km1. Linesville, PA — 10 mi12. Dorset, OH — 16 mi23. Youngstown, OH — 20 mi34. Warren, OH — 27 mi45. Hiram, OH — 31 mi5
  1. Linesville, PA 10 mi (17 km)
  2. Dorset, OH 16 mi (26 km)
  3. Youngstown, OH 20 mi (32 km)
  4. Warren, OH 27 mi (44 km)
  5. Hiram, OH 31 mi (50 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: 41.4992, -80.4681.