U.S. Frost Dates by Weather Station

NOAA station USC00365902 · Pennsylvania

Frost Dates near Industry, PA

NOAA weather station Montgomery Lock and Dam (USC00365902), Pennsylvania · elevation 690 ft (210 m) · hardiness zone 7a*

Industry is the nearest town to the station (1.6 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 15only 1 spring in 10 still has a frost later
  • Typical last frostApril 2850% chance of a frost after it
  • Typical first fall frostOctober 2650% chance of a frost before it
  • Frost-free season178 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season near Industry, PASpring: a frost after April 15 in 9 years out of 10, after April 28 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 26 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 178 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 28First frost ~Oct 26Frost season near Industry, PASpring: a frost after April 15 in 9 years out of 10, after April 28 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 9 in 1 year out of 10, before October 26 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 178 days.JFMAMJJASONDLast frost ~Apr 28First frost ~Oct 26
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 15October 9
50% (typical)April 28October 26
90% (likely)April 15November 6
Frost-free season (32°F, 50% chance)
178 days
Hard frost (28°F), last in spring, 50% chance after
April 17
Hard frost (28°F), first in fall, 50% chance before
November 4

The last 15 years (2006–2020 normals)

Typical last frost April 25 (3 days earlier than the 30-year normal), typical first fall frost October 29 (3 days later). Frost-free season 186 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 Industry: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 15, 20% May 9, 30% May 5, 40% May 1, 50% April 28, 60% April 25, 70% April 22, 80% April 19, 90% April 15. Observed last spring frost in recent years: 2021 April 27, 2022 April 29, 2024 April 26, 2025 April 18, 2026 April 22.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 15Apr 28Apr 152021: April 272022: April 292024: April 262025: April 182026: April 22Fall near Industry: chance of a frost before this dateFall, chance of a frost before the date: 10% October 9, 20% October 16, 30% October 20, 40% October 23, 50% October 26, 60% October 28, 70% October 31, 80% November 2, 90% November 6. Observed first fall frost in recent years: 2021 November 4, 2023 November 1, 2024 October 28, 2025 November 10.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 9Oct 26Nov 62021: November 42023: November 12024: October 282025: November 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 27November 4
2022April 29incomplete record
2023incomplete recordNovember 1
2024April 26October 28
2025April 18November 10
2026April 22season not over yet

What these dates mean

Setting out tender crops on April 15 in the Industry area carries a 90 % chance that a light frost will still occur later in the season, making it a gamble for growers. The cautious spring date to begin tender crops is May 15, when the chance of a frost later than that date drops to 10 %.

April 28 is the 50 % light-frost date in spring, meaning there is a 50 % chance of a frost later than this date, while October 26 is the 50 % light-frost date in fall, with a 50 % chance of a frost earlier than this date. The 50 % hard-frost dates are April 17 and November 4; a hard frost at 28 °F can damage plants that would otherwise survive a light frost at 32 °F. For a cautious fall plan, October 9 is used, when only a 10 % chance exists that a frost has arrived earlier.

How to read the probabilities

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

  • Spring: "10% after May 15" 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 9" 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 Industry, PANumbered nearest stations: 1 — Pittsburgh, PA — 14 mi; 2 — Steubenville, OH — 23 mi; 3 — New Castle, PA — 26 mi; 4 — Butler, PA — 28 mi; 5 — Slippery Rock, PA — 33 mi.PAOHWV25 mi · 40 km1. Pittsburgh, PA — 14 mi12. Steubenville, OH — 23 mi23. New Castle, PA — 26 mi34. Butler, PA — 28 mi45. Slippery Rock, PA — 33 mi5
  1. Pittsburgh, PA 14 mi (23 km)
  2. Steubenville, OH 23 mi (36 km)
  3. New Castle, PA 26 mi (41 km)
  4. Butler, PA 28 mi (45 km)
  5. Slippery Rock, PA 33 mi (53 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: 40.6475, -80.3861.