U.S. Frost Dates by Weather Station

NOAA station USC00252805 · Nebraska

Frost Dates for Ewing, NE

NOAA weather station Ewing (USC00252805), Nebraska · elevation 1854 ft (565 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 21only 1 spring in 10 still has a frost later
  • Typical last frostMay 750% chance of a frost after it
  • Typical first fall frostSeptember 3050% chance of a frost before it
  • Frost-free season144 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Ewing, NESpring: a frost after April 24 in 9 years out of 10, after May 7 in half of the years, after May 21 in 1 year out of 10. Fall: the first frost comes before September 14 in 1 year out of 10, before September 30 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 144 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 7First frost ~Sep 30Frost season at Ewing, NESpring: a frost after April 24 in 9 years out of 10, after May 7 in half of the years, after May 21 in 1 year out of 10. Fall: the first frost comes before September 14 in 1 year out of 10, before September 30 in half of the years, before October 13 in 9 years out of 10. Typical frost-free season: 144 days.JFMAMJJASONDLast frost ~May 7First frost ~Sep 30
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 21September 14
50% (typical)May 7September 30
90% (likely)April 24October 13
Frost-free season (32°F, 50% chance)
144 days
Hard frost (28°F), last in spring, 50% chance after
April 29
Hard frost (28°F), first in fall, 50% chance before
October 7

The last 15 years (2006–2020 normals)

Typical last frost May 7 (same as the 30-year normal), typical first fall frost October 2 (2 days later). Frost-free season 146 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 Ewing: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 21, 20% May 16, 30% May 12, 40% May 9, 50% May 7, 60% May 4, 70% May 2, 80% April 29, 90% April 24.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 21May 7Apr 24Fall at Ewing: chance of a frost before this dateFall, chance of a frost before the date: 10% September 14, 20% September 21, 30% September 24, 40% September 27, 50% September 30, 60% October 2, 70% October 4, 80% October 8, 90% October 13.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 14Sep 30Oct 13
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.

What these dates mean

September 14 marks the cautious fall date in Ewing for finishing the harvest; only a 10 % chance of a light frost has arrived before then. For tender crops the season begins with the cautious spring date of May 21, when a light frost later than that date is still only a 10 % risk, while planting as early as April 24 carries a 90 % gamble.

The 50 % light-frost dates—May 7 in spring and September 30 in fall—represent the point where there is a 50 % chance of a frost later than the date in spring and a 50 % chance of a frost earlier than the date in fall. The median hard-frost dates are April 29 and October 7; a hard frost at 28 °F can damage or kill plants that survive a 32 °F light frost, so it is a more critical threshold for gardeners.

How to read the probabilities

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

  • Spring: "10% after May 21" 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 14" 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 Ewing, NENumbered nearest stations: 1 — O'Neill, NE — 21 mi; 2 — Elgin, NE — 23 mi; 3 — Oakdale, NE — 24 mi; 4 — Atkinson, NE — 39 mi; 5 — Lynch, NE — 40 mi.NESD25 mi · 40 km1. O'Neill, NE — 21 mi12. Elgin, NE — 23 mi23. Oakdale, NE — 24 mi34. Atkinson, NE — 39 mi45. Lynch, NE — 40 mi5
  1. O'Neill, NE 21 mi (34 km)
  2. Elgin, NE 23 mi (38 km)
  3. Oakdale, NE 24 mi (38 km)
  4. Atkinson, NE 39 mi (63 km)
  5. Lynch, NE 40 mi (64 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: 42.2611, -98.3417.