U.S. Frost Dates by Weather Station

NOAA station USC00292030 · New Mexico

Frost Dates for Conchas Dam, NM

NOAA weather station Conchas Dam (USC00292030), New Mexico · elevation 4244 ft (1294 m) · hardiness zone 7b*

  • Lower-risk planting dateafter April 21only 1 spring in 10 still has a frost later
  • Typical last frostApril 450% chance of a frost after it
  • Typical first fall frostNovember 250% chance of a frost before it
  • Frost-free season210 daystypical year, 32°F
  • Hardiness zone7bcalculated*

The year at a glance

Frost season at Conchas Dam, NMSpring: a frost after March 18 in 9 years out of 10, after April 4 in half of the years, after April 21 in 1 year out of 10. Fall: the first frost comes before October 19 in 1 year out of 10, before November 2 in half of the years, before November 16 in 9 years out of 10. Typical frost-free season: 210 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 4First frost ~Nov 2Frost season at Conchas Dam, NMSpring: a frost after March 18 in 9 years out of 10, after April 4 in half of the years, after April 21 in 1 year out of 10. Fall: the first frost comes before October 19 in 1 year out of 10, before November 2 in half of the years, before November 16 in 9 years out of 10. Typical frost-free season: 210 days.JFMAMJJASONDLast frost ~Apr 4First frost ~Nov 2
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 21October 19
50% (typical)April 4November 2
90% (likely)March 18November 16
Frost-free season (32°F, 50% chance)
210 days
Hard frost (28°F), last in spring, 50% chance after
March 23
Hard frost (28°F), first in fall, 50% chance before
November 12

The last 15 years (2006–2020 normals)

Typical last frost April 5 (1 day later than the 30-year normal), typical first fall frost November 1 (1 day earlier). Frost-free season 210 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 Conchas Dam: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 21, 20% April 15, 30% April 10, 40% April 7, 50% April 4, 60% April 1, 70% March 29, 80% March 25, 90% March 18. Observed last spring frost in recent years: 2021 April 21, 2022 April 14, 2023 April 23, 2024 March 27.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 21Apr 4Mar 182021: April 212022: April 142023: April 232024: March 27Fall at Conchas Dam: chance of a frost before this dateFall, chance of a frost before the date: 10% October 19, 20% October 24, 30% October 28, 40% October 31, 50% November 2, 60% November 4, 70% November 7, 80% November 11, 90% November 16. Observed first fall frost in recent years: 2021 November 13, 2023 October 29, 2024 November 7.Fall: first frostChance of a frost before this date10%50%90%Nov 1Oct 19Nov 2Nov 162021: November 132023: October 292024: November 7
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 21November 13
2022April 14incomplete record
2023April 23October 29
2024March 27November 7
2025incomplete recordincomplete record
2026incomplete recordseason not over yet

What these dates mean

April 21 marks the cautious spring date for Conchas Dam, giving a gardener only a 10 % chance that a light frost will still occur later and allowing tender crops to be set out with confidence. The 50 % spring light-frost date is April 4; at that point a frost is equally likely to arrive later as to have already passed.

For the fall, the cautious date to finish harvesting tender crops is October 19, when there is just a 10 % chance a light frost has arrived earlier. The 50 % fall light-frost date is November 2, and the median hard-frost dates are March 23 in spring and November 12 in fall, indicating the moment a 28 °F frost is as likely as not.

A hard frost at 28 °F can damage plants more severely than a light frost at 32 °F, so those dates are especially important for protecting crops.

How to read the probabilities

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

  • Spring: "10% after April 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 October 19" 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 Conchas Dam, NMNumbered nearest stations: 1 — Mosquero, NM — 31 mi; 2 — Tucumcari, NM — 32 mi; 3 — Ragland, NM — 50 mi; 4 — Dilia, NM — 51 mi; 5 — San Jon, NM — 53 mi.NM25 mi · 40 km1. Mosquero, NM — 31 mi12. Tucumcari, NM — 32 mi23. Ragland, NM — 50 mi34. Dilia, NM — 51 mi45. San Jon, NM — 53 mi5
  1. Mosquero, NM 31 mi (49 km)
  2. Tucumcari, NM 32 mi (51 km)
  3. Ragland, NM 50 mi (80 km)
  4. Dilia, NM 51 mi (82 km)
  5. San Jon, NM 53 mi (85 km)

Sources

* Hardiness zone 7b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 35.4072, -104.1906.