U.S. Frost Dates by Weather Station

NOAA station USW00003160 · Nevada

Frost Dates for Mercury Desert Rock Airport, NV

NOAA weather station Mercury Desert Rock Airport (USW00003160), Nevada · elevation 3230 ft (985 m) · hardiness zone 8b*

  • Lower-risk planting dateafter April 9only 1 spring in 10 still has a frost later
  • Typical last frostMarch 1650% chance of a frost after it
  • Typical first fall frostNovember 1750% chance of a frost before it
  • Frost-free season242 daystypical year, 32°F
  • Hardiness zone8bcalculated*

The year at a glance

Frost season at Mercury Desert Rock Airport, NVSpring: a frost after February 22 in 9 years out of 10, after March 16 in half of the years, after April 9 in 1 year out of 10. Fall: the first frost comes before October 31 in 1 year out of 10, before November 17 in half of the years, before December 1 in 9 years out of 10. Typical frost-free season: 242 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 16First frost ~Nov 17Frost season at Mercury Desert Rock Airport, NVSpring: a frost after February 22 in 9 years out of 10, after March 16 in half of the years, after April 9 in 1 year out of 10. Fall: the first frost comes before October 31 in 1 year out of 10, before November 17 in half of the years, before December 1 in 9 years out of 10. Typical frost-free season: 242 days.JFMAMJJASONDLast frost ~Mar 16First frost ~Nov 17
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 9October 31
50% (typical)March 16November 17
90% (likely)February 22December 1
Frost-free season (32°F, 50% chance)
242 days
Hard frost (28°F), last in spring, 50% chance after
February 20
Hard frost (28°F), first in fall, 50% chance before
November 30

The last 15 years (2006–2020 normals)

Typical last frost March 11 (5 days earlier than the 30-year normal), typical first fall frost November 17. Frost-free season 244 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 Mercury Desert Rock Airport: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 9, 20% April 3, 30% March 29, 40% March 23, 50% March 16, 60% March 11, 70% March 6, 80% March 1, 90% February 22. Observed last spring frost in recent years: 2021 March 14, 2022 April 13, 2023 April 5, 2024 April 6, 2025 March 15, 2026 February 21.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 9Mar 16Feb 222021: March 142022: April 132023: April 52024: April 62025: March 152026: February 21Fall at Mercury Desert Rock Airport: chance of a frost before this dateFall, chance of a frost before the date: 10% October 31, 20% November 6, 30% November 10, 40% November 14, 50% November 17, 60% November 20, 70% November 23, 80% November 26, 90% December 1. Observed first fall frost in recent years: 2021 December 10, 2022 November 12, 2023 November 11, 2024 November 14, 2025 December 2.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 31Nov 17Dec 12021: December 102022: November 122023: November 112024: November 142025: December 2
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
2021March 14December 10
2022April 13November 12
2023April 5November 11
2024April 6November 14
2025March 15December 2
2026February 21season not over yet

What these dates mean

The 242 days between the 32°F 50% dates at Mercury Desert Rock Airport—March 16 and November 17—frame the interval in which light frosts are less than even-odds. For a gardener, the 50% dates indicate the point at which a light frost is equally likely to occur earlier or later; they are not themselves frost dates but markers of median probability.

In spring the cautious date for setting out tender crops is the late April 9 date, which carries only a 10% chance of a later frost, while the February 22 date represents a 90% chance and is a gamble. In fall the cautious date to finish harvesting tender crops is the early October 31 date, with a 10% chance of an earlier frost, and the December 1 date reflects a 90% chance and is a gamble.

A hard frost at 28°F, shown by the median dates February 20 and November 30, can damage plants more severely than a light frost at 32°F.

How to read the probabilities

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

  • Spring: "10% after April 9" 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 31" 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 Mercury Desert Rock Airport, NVNumbered nearest stations: 1 — Pahrump, NV — 25 mi; 2 — Desert NWR, NV — 39 mi; 3 — Overton, NV — 87 mi; 4 — Caliente, NV — 107 mi; 5 — Tonopah, NV — 115 mi.NVCAUTAZ50 mi · 80 km1. Pahrump, NV — 25 mi12. Desert NWR, NV — 39 mi23. Overton, NV — 87 mi34. Caliente, NV — 107 mi45. Tonopah, NV — 115 mi5
  1. Pahrump, NV 25 mi (40 km)
  2. Desert NWR, NV 39 mi (63 km)
  3. Overton, NV 87 mi (140 km)
  4. Caliente, NV 107 mi (173 km)
  5. Tonopah, NV 115 mi (185 km)

Sources

* Hardiness zone 8b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 36.6206, -116.0278.