U.S. Frost Dates by Weather Station

NOAA station USC00186350 · Maryland

Frost Dates near Bladensburg, MD

NOAA weather station National Arboretum DC (USC00186350), Maryland · elevation 50 ft (15 m) · hardiness zone 8a*

Bladensburg is the nearest town to the station (2.7 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 April 11only 1 spring in 10 still has a frost later
  • Typical last frostMarch 2950% chance of a frost after it
  • Typical first fall frostNovember 850% chance of a frost before it
  • Frost-free season224 daystypical year, 32°F
  • Hardiness zone8acalculated*

The year at a glance

Frost season near Bladensburg, MDSpring: a frost after March 15 in 9 years out of 10, after March 29 in half of the years, after April 11 in 1 year out of 10. Fall: the first frost comes before October 26 in 1 year out of 10, before November 8 in half of the years, before November 23 in 9 years out of 10. Typical frost-free season: 224 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 29First frost ~Nov 8Frost season near Bladensburg, MDSpring: a frost after March 15 in 9 years out of 10, after March 29 in half of the years, after April 11 in 1 year out of 10. Fall: the first frost comes before October 26 in 1 year out of 10, before November 8 in half of the years, before November 23 in 9 years out of 10. Typical frost-free season: 224 days.JFMAMJJASONDLast frost ~Mar 29First frost ~Nov 8
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 11October 26
50% (typical)March 29November 8
90% (likely)March 15November 23
Frost-free season (32°F, 50% chance)
224 days
Hard frost (28°F), last in spring, 50% chance after
March 17
Hard frost (28°F), first in fall, 50% chance before
November 20

The last 15 years (2006–2020 normals)

Typical last frost March 30 (1 day later than the 30-year normal), typical first fall frost November 10 (2 days later). Frost-free season 226 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 Bladensburg: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 11, 20% April 6, 30% April 3, 40% March 31, 50% March 29, 60% March 27, 70% March 24, 80% March 20, 90% March 15. Observed last spring frost in recent years: 2021 April 3, 2022 March 30, 2023 May 10.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 11Mar 29Mar 152021: April 32022: March 302023: May 10Fall near Bladensburg: chance of a frost before this dateFall, chance of a frost before the date: 10% October 26, 20% October 31, 30% November 2, 40% November 5, 50% November 8, 60% November 10, 70% November 13, 80% November 17, 90% November 23. Observed first fall frost in recent years: 2021 November 6, 2022 November 18.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 26Nov 8Nov 232021: November 62022: November 18
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 3November 6
2022March 30November 18
2023May 10incomplete record
2024incomplete recordincomplete record
2025incomplete recordincomplete record
2026incomplete recordseason not over yet

What these dates mean

In the Bladensburg area there are 224 days between the 32°F 50% dates, March 29 and November 8, and these days contain the window when tender crops can typically be grown. The 50% dates indicate a fifty-fifty chance of a light frost occurring later in spring or earlier in fall, so gardeners can use them as a reference for the overall season.

For a cautious spring plan the tender-crop setting date is April 11, which carries only a ten percent chance of a later frost; planting earlier on March 15 involves a ninety percent chance and is a gamble. In fall the cautious date to finish harvesting tender crops is October 26, with a ten percent chance that a frost has already arrived, while extending to November 23 entails a ninety percent risk. A hard frost at 28°F, whose 50% dates are March 17 and November 20, can injure plants that would survive a light frost, making it the more serious threat.

How to read the probabilities

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

  • Spring: "10% after April 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 26" 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 Bladensburg, MDNumbered nearest stations: 1 — near Arlington, VA — 6 mi; 2 — Beltsville, MD — 8 mi; 3 — near Baltimore, MD — 23 mi; 4 — near Oak Hill, VA — 27 mi; 5 — near Loudoun Valley Estates, VA — 28 mi.VAWV25 mi · 40 km1. near Arlington, VA — 6 mi12. Beltsville, MD — 8 mi23. near Baltimore, MD — 23 mi34. near Oak Hill, VA — 27 mi45. near Loudoun Valley Estates, VA — 28 mi5
  1. near Arlington, VA 6 mi (9 km)
  2. Beltsville, MD 8 mi (13 km)
  3. near Baltimore, MD 23 mi (38 km)
  4. near Oak Hill, VA 27 mi (43 km)
  5. near Loudoun Valley Estates, VA 28 mi (45 km)

Sources

* Hardiness zone 8a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 38.9133, -76.97.