U.S. Frost Dates by Weather Station

NOAA station USW00094702 · Connecticut

Frost Dates near Bridgeport, CT

NOAA weather station Bridgeport Sikorsky Memorial Airport (USW00094702), Connecticut · elevation 5 ft (2 m) · hardiness zone 7a*

Bridgeport is the nearest town to the station (3.5 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 17only 1 spring in 10 still has a frost later
  • Typical last frostApril 550% chance of a frost after it
  • Typical first fall frostNovember 650% chance of a frost before it
  • Frost-free season216 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season near Bridgeport, CTSpring: a frost after March 25 in 9 years out of 10, after April 5 in half of the years, after April 17 in 1 year out of 10. Fall: the first frost comes before October 25 in 1 year out of 10, before November 6 in half of the years, before November 20 in 9 years out of 10. Typical frost-free season: 216 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 5First frost ~Nov 6Frost season near Bridgeport, CTSpring: a frost after March 25 in 9 years out of 10, after April 5 in half of the years, after April 17 in 1 year out of 10. Fall: the first frost comes before October 25 in 1 year out of 10, before November 6 in half of the years, before November 20 in 9 years out of 10. Typical frost-free season: 216 days.JFMAMJJASONDLast frost ~Apr 5First frost ~Nov 6
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)April 17October 25
50% (typical)April 5November 6
90% (likely)March 25November 20
Frost-free season (32°F, 50% chance)
216 days
Hard frost (28°F), last in spring, 50% chance after
March 26
Hard frost (28°F), first in fall, 50% chance before
November 19

The last 15 years (2006–2020 normals)

Typical last frost April 4 (1 day earlier than the 30-year normal), typical first fall frost November 8 (2 days later). Frost-free season 216 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 Bridgeport: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 17, 20% April 13, 30% April 9, 40% April 7, 50% April 5, 60% April 3, 70% April 1, 80% March 30, 90% March 25. Observed last spring frost in recent years: 2021 April 3, 2022 March 30, 2023 April 3, 2024 March 24, 2025 April 9, 2026 April 9.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 17Apr 5Mar 252021: April 32022: March 302023: April 32024: March 242025: April 92026: April 9Fall near Bridgeport: chance of a frost before this dateFall, chance of a frost before the date: 10% October 25, 20% October 30, 30% November 1, 40% November 4, 50% November 6, 60% November 9, 70% November 12, 80% November 16, 90% November 20. Observed first fall frost in recent years: 2021 November 17, 2022 November 15, 2023 November 2, 2024 November 13, 2025 November 7.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 25Nov 6Nov 202021: November 172022: November 152023: November 22024: November 132025: November 7
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 17
2022March 30November 15
2023April 3November 2
2024March 24November 13
2025April 9November 7
2026April 9season not over yet

What these dates mean

Setting out tender crops on March 25 in the Bridgeport area is a gamble, because a frost later than that date occurs with a 90% chance.

For gardeners, the 50% light-frost date in spring is April 5 and the 50% light-frost date in fall is November 6; each marks the point where a light frost has a 50% chance of having occurred by that date, and together they define the 216-day frost-free interval recorded over 30 years.

April 17 is the cautious spring date with only a 10% chance of a frost later, while October 25 is the cautious fall date with only a 10% chance of a frost earlier; the hard-frost median dates are March 26 in spring and November 19 in fall, and 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 April 17" 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 25" 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 Bridgeport, CTNumbered nearest stations: 1 — near Islip, NY — 25 mi; 2 — Riverhead, NY — 25 mi; 3 — near Purchase, NY — 31 mi; 4 — Yorktown Heights, NY — 36 mi; 5 — Bridgehampton, NY — 46 mi.NYCTNJ25 mi · 40 km1. near Islip, NY — 25 mi12. Riverhead, NY — 25 mi23. near Purchase, NY — 31 mi34. Yorktown Heights, NY — 36 mi45. Bridgehampton, NY — 46 mi5
  1. near Islip, NY 25 mi (41 km)
  2. Riverhead, NY 25 mi (41 km)
  3. near Purchase, NY 31 mi (50 km)
  4. Yorktown Heights, NY 36 mi (57 km)
  5. Bridgehampton, NY 46 mi (73 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: 41.1583, -73.1289.