U.S. Frost Dates by Weather Station

NOAA station USC00257715 · Nebraska

Frost Dates for Seward, NE

NOAA weather station Seward (USC00257715), Nebraska · elevation 1445 ft (440 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 7only 1 spring in 10 still has a frost later
  • Typical last frostApril 2650% chance of a frost after it
  • Typical first fall frostOctober 1250% chance of a frost before it
  • Frost-free season169 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Seward, NESpring: a frost after April 11 in 9 years out of 10, after April 26 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 12 in half of the years, before October 24 in 9 years out of 10. Typical frost-free season: 169 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 26First frost ~Oct 12Frost season at Seward, NESpring: a frost after April 11 in 9 years out of 10, after April 26 in half of the years, after May 7 in 1 year out of 10. Fall: the first frost comes before September 28 in 1 year out of 10, before October 12 in half of the years, before October 24 in 9 years out of 10. Typical frost-free season: 169 days.JFMAMJJASONDLast frost ~Apr 26First frost ~Oct 12
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 27 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 7September 28
50% (typical)April 26October 12
90% (likely)April 11October 24
Frost-free season (32°F, 50% chance)
169 days
Hard frost (28°F), last in spring, 50% chance after
April 15
Hard frost (28°F), first in fall, 50% chance before
October 20

The last 15 years (2006–2020 normals)

Typical last frost April 25 (1 day earlier than the 30-year normal), typical first fall frost October 15 (3 days later). Frost-free season 172 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 Seward: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 7, 20% May 3, 30% May 1, 40% April 28, 50% April 26, 60% April 22, 70% April 19, 80% April 16, 90% April 11. Observed last spring frost in recent years: 2022 April 27, 2023 April 25, 2024 April 22, 2025 April 9, 2026 April 19.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 7Apr 26Apr 112022: April 272023: April 252024: April 222025: April 92026: April 19Fall at Seward: chance of a frost before this dateFall, chance of a frost before the date: 10% September 28, 20% October 2, 30% October 6, 40% October 9, 50% October 12, 60% October 14, 70% October 17, 80% October 20, 90% October 24. Observed first fall frost in recent years: 2022 October 8, 2023 October 28, 2024 October 14, 2025 October 23.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 28Oct 12Oct 242022: October 82023: October 282024: October 142025: October 23
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
2021no datano data
2022April 27October 8
2023April 25October 28
2024April 22October 14
2025April 9October 23
2026April 19season not over yet

What these dates mean

September 28 is the cautious fall date in Seward for finishing the harvest, with only a 10 % chance that a light frost has arrived earlier. By contrast, October 24 carries a 90 % chance that a light frost will already be present, making it a gamble for tender crops.

For a gardener, the 50 % dates indicate when light-frost risk is evenly split: April 26 in spring and October 12 in fall. The median hard-frost dates are April 15 and October 20, marking the point at which a 28 °F frost is as likely as not. These dates help gauge the balance of risk without implying safety.

A cautious planting plan uses May 7 as the spring date with a 10 % chance of a later light frost, and September 28 as the fall date with a 10 % chance of an earlier light frost. A hard frost matters more because 28 °F can injure plants that survive the milder 32 °F light frost.

How to read the probabilities

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

  • Spring: "10% after May 7" 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 Seward, NENumbered nearest stations: 1 — Lincoln, NE — 18 mi; 2 — Crete, NE — 23 mi; 3 — David City, NE — 24 mi; 4 — Osceola, NE — 31 mi; 5 — Mead, NE — 36 mi.IA25 mi · 40 km1. Lincoln, NE — 18 mi12. Crete, NE — 23 mi23. David City, NE — 24 mi34. Osceola, NE — 31 mi45. Mead, NE — 36 mi5
  1. Lincoln, NE 18 mi (29 km)
  2. Crete, NE 23 mi (37 km)
  3. David City, NE 24 mi (39 km)
  4. Osceola, NE 31 mi (50 km)
  5. Mead, NE 36 mi (58 km)

Sources

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

Station coordinates: 40.8997, -97.0908.