U.S. Frost Dates by Weather Station

NOAA station USC00251145 · Nebraska

Frost Dates for Bridgeport, NE

NOAA weather station Bridgeport (USC00251145), Nebraska · elevation 3666 ft (1117 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 23only 1 spring in 10 still has a frost later
  • Typical last frostMay 850% chance of a frost after it
  • Typical first fall frostOctober 350% chance of a frost before it
  • Frost-free season147 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Bridgeport, NESpring: a frost after April 26 in 9 years out of 10, after May 8 in half of the years, after May 23 in 1 year out of 10. Fall: the first frost comes before September 21 in 1 year out of 10, before October 3 in half of the years, before October 15 in 9 years out of 10. Typical frost-free season: 147 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 8First frost ~Oct 3Frost season at Bridgeport, NESpring: a frost after April 26 in 9 years out of 10, after May 8 in half of the years, after May 23 in 1 year out of 10. Fall: the first frost comes before September 21 in 1 year out of 10, before October 3 in half of the years, before October 15 in 9 years out of 10. Typical frost-free season: 147 days.JFMAMJJASONDLast frost ~May 8First frost ~Oct 3
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)May 23September 21
50% (typical)May 8October 3
90% (likely)April 26October 15
Frost-free season (32°F, 50% chance)
147 days
Hard frost (28°F), last in spring, 50% chance after
April 29
Hard frost (28°F), first in fall, 50% chance before
October 13

The last 15 years (2006–2020 normals)

Typical last frost May 6 (2 days earlier than the 30-year normal), typical first fall frost October 5 (2 days later). Frost-free season 149 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 Bridgeport: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 23, 20% May 17, 30% May 14, 40% May 11, 50% May 8, 60% May 5, 70% May 3, 80% April 30, 90% April 26. Observed last spring frost in recent years: 2021 May 13.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 23May 8Apr 262021: May 13Fall at Bridgeport: chance of a frost before this dateFall, chance of a frost before the date: 10% September 21, 20% September 25, 30% September 28, 40% October 1, 50% October 3, 60% October 5, 70% October 8, 80% October 11, 90% October 15. Observed first fall frost in recent years: 2021 September 17.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 21Oct 3Oct 152021: September 17
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 13September 17
2022incomplete recordno data
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

The cautious fall date for finishing the harvest in Bridgeport is September 21, when there is only a 10 % chance that a light frost has arrived.

Gardeners can use the 50 % light-frost dates, May 8 in spring and October 3 in fall, as the points at which frost is equally likely to occur later or earlier. A cautious spring plan for tender crops relies on May 23, the date with a 10 % chance of a later frost, while a cautious fall plan uses September 21. The 28 °F hard-frost 50 % dates are April 29 and October 13, and a hard frost can damage plants that would survive a 32 °F light frost. The median light-frost window spans 147 days between May 8 and October 3, based on 29 years of record.

How to read the probabilities

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

  • Spring: "10% after May 23" 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 21" 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, NENumbered nearest stations: 1 — near Scottsbluff, NE — 29 mi; 2 — Oshkosh, NE — 43 mi; 3 — Lodgepole, NE — 43 mi; 4 — Harrisburg, NE — 44 mi; 5 — Sedgwick, CO — 63 mi.NECOWY25 mi · 40 km1. near Scottsbluff, NE — 29 mi12. Oshkosh, NE — 43 mi23. Lodgepole, NE — 43 mi34. Harrisburg, NE — 44 mi45. Sedgwick, CO — 63 mi5
  1. near Scottsbluff, NE 29 mi (46 km)
  2. Oshkosh, NE 43 mi (70 km)
  3. Lodgepole, NE 43 mi (70 km)
  4. Harrisburg, NE 44 mi (71 km)
  5. Sedgwick, CO 63 mi (102 km)

Sources

* Hardiness zone 5a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 41.6681, -103.1039.