U.S. Frost Dates by Weather Station

NOAA station USC00297008 · New Mexico

Frost Dates for Portales, NM

NOAA weather station Portales (USC00297008), New Mexico · elevation 4010 ft (1222 m) · hardiness zone 7a*

  • Lower-risk planting dateafter April 30only 1 spring in 10 still has a frost later
  • Typical last frostApril 1550% chance of a frost after it
  • Typical first fall frostOctober 2650% chance of a frost before it
  • Frost-free season193 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Portales, NMSpring: a frost after March 30 in 9 years out of 10, after April 15 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 12 in 1 year out of 10, before October 26 in half of the years, before November 7 in 9 years out of 10. Typical frost-free season: 193 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 15First frost ~Oct 26Frost season at Portales, NMSpring: a frost after March 30 in 9 years out of 10, after April 15 in half of the years, after April 30 in 1 year out of 10. Fall: the first frost comes before October 12 in 1 year out of 10, before October 26 in half of the years, before November 7 in 9 years out of 10. Typical frost-free season: 193 days.JFMAMJJASONDLast frost ~Apr 15First frost ~Oct 26
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)April 30October 12
50% (typical)April 15October 26
90% (likely)March 30November 7
Frost-free season (32°F, 50% chance)
193 days
Hard frost (28°F), last in spring, 50% chance after
April 2
Hard frost (28°F), first in fall, 50% chance before
November 4

The last 15 years (2006–2020 normals)

Typical last frost April 18 (3 days later than the 30-year normal), typical first fall frost October 24 (2 days earlier). Frost-free season 190 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 Portales: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 30, 20% April 25, 30% April 21, 40% April 18, 50% April 15, 60% April 12, 70% April 8, 80% April 4, 90% March 30. Observed last spring frost in recent years: 2021 April 21, 2022 April 14, 2023 April 29, 2024 April 10, 2025 April 30.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 30Apr 15Mar 302021: April 212022: April 142023: April 292024: April 102025: April 30Fall at Portales: chance of a frost before this dateFall, chance of a frost before the date: 10% October 12, 20% October 17, 30% October 20, 40% October 23, 50% October 26, 60% October 29, 70% November 1, 80% November 3, 90% November 7. Observed first fall frost in recent years: 2021 October 16, 2022 November 11, 2023 October 29, 2024 October 31.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 12Oct 26Nov 72021: October 162022: November 112023: October 292024: October 31
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 21October 16
2022April 14November 11
2023April 29October 29
2024April 10October 31
2025April 30incomplete record
2026incomplete recordseason not over yet

What these dates mean

October 12 marks the cautious fall date in Portales for finishing the harvest, with only a 10 % chance that a light frost has arrived earlier.

The 50% spring date is April 15, and the 50% fall date is October 26; on those days the odds of a frost are even. For a low-risk schedule, gardeners use the cautious spring date of April 30 (10 % chance of a later frost) and the cautious fall date of October 12 (10 % chance of an earlier frost). Planting or harvesting before April 30 or after October 12 raises the probability of frost exposure.

A hard frost at 28 °F, indicated by the median dates April 2 in spring and November 4 in fall, can damage plant tissue that would 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 April 30" 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 12" 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 Portales, NMNumbered nearest stations: 1 — Melrose, NM — 23 mi; 2 — near Muleshoe, TX — 36 mi; 3 — Morton, TX — 46 mi; 4 — Ragland, NM — 48 mi; 5 — Friona, TX — 48 mi.NMTX25 mi · 40 km1. Melrose, NM — 23 mi12. near Muleshoe, TX — 36 mi23. Morton, TX — 46 mi34. Ragland, NM — 48 mi45. Friona, TX — 48 mi5
  1. Melrose, NM 23 mi (38 km)
  2. near Muleshoe, TX 36 mi (57 km)
  3. Morton, TX 46 mi (75 km)
  4. Ragland, NM 48 mi (77 km)
  5. Friona, TX 48 mi (78 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: 34.1742, -103.3519.