U.S. Frost Dates by Weather Station

NOAA station USC00188065 · Maryland

Frost Dates near Westernport, MD

NOAA weather station Savage River Dam (USC00188065), Maryland · elevation 1495 ft (456 m) · hardiness zone 6b*

Westernport is the nearest town to the station (5.3 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 2950% chance of a frost after it
  • Typical first fall frostOctober 2050% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone6bcalculated*

The year at a glance

Frost season near Westernport, MDSpring: a frost after April 11 in 9 years out of 10, after April 29 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 20 in half of the years, before November 2 in 9 years out of 10. Typical frost-free season: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 29First frost ~Oct 20Frost season near Westernport, MDSpring: a frost after April 11 in 9 years out of 10, after April 29 in half of the years, after May 15 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 20 in half of the years, before November 2 in 9 years out of 10. Typical frost-free season: 174 days.JFMAMJJASONDLast frost ~Apr 29First frost ~Oct 20
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 15October 4
50% (typical)April 29October 20
90% (likely)April 11November 2
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 12
Hard frost (28°F), first in fall, 50% chance before
November 1

The last 15 years (2006–2020 normals)

Typical last frost April 23 (6 days earlier than the 30-year normal), typical first fall frost October 24 (4 days later). Frost-free season 180 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 Westernport: 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 29, 60% April 25, 70% April 21, 80% April 17, 90% April 11. Observed last spring frost in recent years: 2021 April 25, 2022 April 30, 2023 April 26, 2024 April 23, 2025 April 10, 2026 April 22.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 15Apr 29Apr 112021: April 252022: April 302023: April 262024: April 232025: April 102026: April 22Fall near Westernport: chance of a frost before this dateFall, chance of a frost before the date: 10% October 4, 20% October 9, 30% October 13, 40% October 16, 50% October 20, 60% October 24, 70% October 26, 80% October 30, 90% November 2. Observed first fall frost in recent years: 2021 November 3, 2022 October 9, 2023 November 2, 2024 October 28, 2025 October 26.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 4Oct 20Nov 22021: November 32022: October 92023: November 22024: October 282025: October 26
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 25November 3
2022April 30October 9
2023April 26November 2
2024April 23October 28
2025April 10October 26
2026April 22season not over yet

What these dates mean

May 15 is the cautious spring date for the Westernport area; with only a 10 % chance of a light frost after that day, a gardener can plan to set out tender crops with minimal risk.

The 50 % light-frost dates are April 29 and October 20. April 29 marks the point where there is a 50 % chance of a frost later than this date, while October 20 marks the point where there is a 50 % chance of a frost earlier than this date. The hard-frost 50 % dates are April 12 and November 1, and a hard frost at 28 °F can damage plants that survive a light frost at 32 °F, making those dates more critical for protection.

October 4 is the cautious fall date; with only a 10 % chance of a light frost before that day, a gardener can finish harvesting tender crops with confidence.

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 4" 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 Westernport, MDNumbered nearest stations: 1 — Keyser, WV — 9 mi; 2 — Frostburg, MD — 15 mi; 3 — Oakland, MD — 15 mi; 4 — Cumberland, MD — 22 mi; 5 — Parsons, WV — 40 mi.PAVA25 mi · 40 km1. Keyser, WV — 9 mi12. Frostburg, MD — 15 mi23. Oakland, MD — 15 mi34. Cumberland, MD — 22 mi45. Parsons, WV — 40 mi5
  1. Keyser, WV 9 mi (15 km)
  2. Frostburg, MD 15 mi (24 km)
  3. Oakland, MD 15 mi (25 km)
  4. Cumberland, MD 22 mi (36 km)
  5. Parsons, WV 40 mi (65 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: 39.51, -79.14.