U.S. Frost Dates by Weather Station

NOAA station USC00367477 · Pennsylvania

Frost Dates for Ridgway, PA

NOAA weather station Ridgway (USC00367477), Pennsylvania · elevation 1360 ft (415 m) · hardiness zone 6a*

  • Lower-risk planting dateafter May 28only 1 spring in 10 still has a frost later
  • Typical last frostMay 1350% chance of a frost after it
  • Typical first fall frostOctober 1150% chance of a frost before it
  • Frost-free season150 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Ridgway, PASpring: a frost after April 26 in 9 years out of 10, after May 13 in half of the years, after May 28 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 11 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 150 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 13First frost ~Oct 11Frost season at Ridgway, PASpring: a frost after April 26 in 9 years out of 10, after May 13 in half of the years, after May 28 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 11 in half of the years, before October 26 in 9 years out of 10. Typical frost-free season: 150 days.JFMAMJJASONDLast frost ~May 13First frost ~Oct 11
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 28September 28
50% (typical)May 13October 11
90% (likely)April 26October 26
Frost-free season (32°F, 50% chance)
150 days
Hard frost (28°F), last in spring, 50% chance after
May 1
Hard frost (28°F), first in fall, 50% chance before
October 25

The last 15 years (2006–2020 normals)

Typical last frost May 9 (4 days earlier than the 30-year normal), typical first fall frost October 14 (3 days later). Frost-free season 154 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 Ridgway: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 28, 20% May 24, 30% May 20, 40% May 18, 50% May 13, 60% May 10, 70% May 5, 80% May 1, 90% April 26. Observed last spring frost in recent years: 2021 May 14, 2022 May 9, 2023 May 26, 2024 April 26, 2025 June 2, 2026 May 31.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 28May 13Apr 262021: May 142022: May 92023: May 262024: April 262025: June 22026: May 31Fall at Ridgway: 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 7, 50% October 11, 60% October 14, 70% October 17, 80% October 21, 90% October 26. Observed first fall frost in recent years: 2021 November 4, 2022 October 9, 2023 October 23, 2024 October 11, 2025 August 30.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Nov 1Sep 28Oct 11Oct 262021: November 42022: October 92023: October 232024: October 112025: August 30
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 14November 4
2022May 9October 9
2023May 26October 23
2024April 26October 11
2025June 2August 30
2026May 31season not over yet

What these dates mean

May 28 is the cautious spring date for tender crops in Ridgway, carrying a 10 % chance that a light frost will occur later. Planting on or after that day gives a gardener a low-risk window to set out those sensitive seedlings.

The 50% light-frost dates are May 13 and October 11; each represents a 50 % chance of a frost later (spring) or earlier (fall) than the date. The hard-frost 50% dates are May 1 and October 25, marking the point at which a 28 °F frost is equally likely to have happened. For a cautious fall plan the September 28 date carries only a 10 % chance that a light frost has already arrived, making it the point to finish harvesting tender crops.

A hard frost at 28 °F can damage plant tissue more severely than a light frost at 32 °F, so its timing is a critical consideration for growers in this climate.

How to read the probabilities

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

  • Spring: "10% after May 28" 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 Ridgway, PANumbered nearest stations: 1 — Kane, PA — 18 mi; 2 — Dubois, PA — 18 mi; 3 — Bradford, PA — 27 mi; 4 — Bradford 4 SW Research 5, PA — 33 mi; 5 — Warren, PA — 36 mi.NY25 mi · 40 km1. Kane, PA — 18 mi12. Dubois, PA — 18 mi23. Bradford, PA — 27 mi34. Bradford 4 SW Research 5, PA — 33 mi45. Warren, PA — 36 mi5
  1. Kane, PA 18 mi (29 km)
  2. Dubois, PA 18 mi (30 km)
  3. Bradford, PA 27 mi (44 km)
  4. Bradford 4 SW Research 5, PA 33 mi (53 km)
  5. Warren, PA 36 mi (58 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: 41.4197, -78.7492.