U.S. Frost Dates by Weather Station

NOAA station USC00255925 · Nebraska

Frost Dates for Newport, NE

NOAA weather station Newport (USC00255925), Nebraska · elevation 2230 ft (680 m) · hardiness zone 5a*

  • Lower-risk planting dateafter May 20only 1 spring in 10 still has a frost later
  • Typical last frostMay 650% chance of a frost after it
  • Typical first fall frostOctober 150% chance of a frost before it
  • Frost-free season147 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season at Newport, NESpring: a frost after April 23 in 9 years out of 10, after May 6 in half of the years, after May 20 in 1 year out of 10. Fall: the first frost comes before September 20 in 1 year out of 10, before October 1 in half of the years, before October 14 in 9 years out of 10. Typical frost-free season: 147 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 6First frost ~Oct 1Frost season at Newport, NESpring: a frost after April 23 in 9 years out of 10, after May 6 in half of the years, after May 20 in 1 year out of 10. Fall: the first frost comes before September 20 in 1 year out of 10, before October 1 in half of the years, before October 14 in 9 years out of 10. Typical frost-free season: 147 days.JFMAMJJASONDLast frost ~May 6First frost ~Oct 1
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 20September 20
50% (typical)May 6October 1
90% (likely)April 23October 14
Frost-free season (32°F, 50% chance)
147 days
Hard frost (28°F), last in spring, 50% chance after
April 26
Hard frost (28°F), first in fall, 50% chance before
October 11

The last 15 years (2006–2020 normals)

Typical last frost May 7 (1 day later than the 30-year normal), typical first fall frost October 5 (4 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 Newport: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 20, 20% May 14, 30% May 11, 40% May 8, 50% May 6, 60% May 3, 70% May 1, 80% April 28, 90% April 23.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 20May 6Apr 23Fall at Newport: chance of a frost before this dateFall, chance of a frost before the date: 10% September 20, 20% September 24, 30% September 27, 40% September 29, 50% October 1, 60% October 4, 70% October 7, 80% October 10, 90% October 14.Fall: first frostChance of a frost before this date10%50%90%Oct 1Sep 20Oct 1Oct 14
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

May 20 is the cautious spring date for Newport, offering only a 10 % chance that a light frost will occur later, so a gardener can plan to set out tender crops with minimal risk. The comparable cautious fall date is September 20, when there is a 10 % chance that a light frost has already arrived, marking the time to finish harvesting tender crops.

The 50% dates—May 6 for spring and October 1 for fall—are points at which a light frost has an even chance of occurring later (spring) or earlier (fall). Hard-frost thresholds are higher; the 50% hard-frost dates are April 26 in spring and October 11 in fall, and a hard frost at 28 °F can injure plants that would survive a 32 °F light frost, making it a more critical concern.

How to read the probabilities

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

  • Spring: "10% after May 20" 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 20" 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 Newport, NENumbered nearest stations: 1 — Atkinson, NE — 17 mi; 2 — Ainsworth, NE — 27 mi; 3 — Springview, NE — 28 mi; 4 — Butte, NE — 33 mi; 5 — O'Neill, NE — 36 mi.SD25 mi · 40 km1. Atkinson, NE — 17 mi12. Ainsworth, NE — 27 mi23. Springview, NE — 28 mi34. Butte, NE — 33 mi45. O'Neill, NE — 36 mi5
  1. Atkinson, NE 17 mi (27 km)
  2. Ainsworth, NE 27 mi (43 km)
  3. Springview, NE 28 mi (45 km)
  4. Butte, NE 33 mi (52 km)
  5. O'Neill, NE 36 mi (58 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: 42.6008, -99.3333.