U.S. Frost Dates by Weather Station

NOAA station USW00023153 · Nevada

Frost Dates for Tonopah, NV

NOAA weather station Tonopah (USW00023153), Nevada · elevation 5395 ft (1644 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 24only 1 spring in 10 still has a frost later
  • Typical last frostApril 3050% chance of a frost after it
  • Typical first fall frostOctober 1850% chance of a frost before it
  • Frost-free season169 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Tonopah, NVSpring: a frost after April 13 in 9 years out of 10, after April 30 in half of the years, after May 24 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 18 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 169 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 30First frost ~Oct 18Frost season at Tonopah, NVSpring: a frost after April 13 in 9 years out of 10, after April 30 in half of the years, after May 24 in 1 year out of 10. Fall: the first frost comes before October 4 in 1 year out of 10, before October 18 in half of the years, before November 1 in 9 years out of 10. Typical frost-free season: 169 days.JFMAMJJASONDLast frost ~Apr 30First frost ~Oct 18
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)May 24October 4
50% (typical)April 30October 18
90% (likely)April 13November 1
Frost-free season (32°F, 50% chance)
169 days
Hard frost (28°F), last in spring, 50% chance after
April 17
Hard frost (28°F), first in fall, 50% chance before
October 28

The last 15 years (2006–2020 normals)

Typical last frost April 29 (1 day earlier than the 30-year normal), typical first fall frost October 16 (2 days earlier). Frost-free season 168 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 Tonopah: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 24, 20% May 15, 30% May 7, 40% May 2, 50% April 30, 60% April 26, 70% April 23, 80% April 20, 90% April 13. Observed last spring frost in recent years: 2021 April 28, 2022 May 12, 2023 May 6, 2024 May 8, 2025 April 27, 2026 April 23.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Jun 1May 24Apr 30Apr 132021: April 282022: May 122023: May 62024: May 82025: April 272026: April 23Fall at Tonopah: chance of a frost before this dateFall, chance of a frost before the date: 10% October 4, 20% October 8, 30% October 12, 40% October 15, 50% October 18, 60% October 20, 70% October 23, 80% October 26, 90% November 1. Observed first fall frost in recent years: 2021 October 11, 2022 October 23, 2023 October 27, 2024 October 18, 2025 October 15.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 4Oct 18Nov 12021: October 112022: October 232023: October 272024: October 182025: October 15
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 28October 11
2022May 12October 23
2023May 6October 27
2024May 8October 18
2025April 27October 15
2026April 23season not over yet

What these dates mean

October 4 is the cautious fall date for finishing the harvest of tender crops in Tonopah, as it carries only a 10 % chance that a light frost has arrived earlier. By contrast, November 1 carries a 90 % chance that a light frost will already be present, making it a gamble for late-season tender plants.

In spring, the cautious date for setting out tender crops is May 24, when there is just a 10 % chance of a light frost occurring later. The 50 % light-frost dates—April 30 in spring and October 18 in fall—represent the point at which a light frost is equally likely. The 50 % hard-frost dates are April 17 in spring and October 28 in fall.

Hard frost at 28 °F matters more than a light frost at 32 °F because it can damage plants that would otherwise survive the milder temperature.

How to read the probabilities

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

  • Spring: "10% after May 24" 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 4" 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 Tonopah, NVNumbered nearest stations: 1 — Smoky Valley - Carvers, NV — 51 mi; 2 — Dyer, NV — 58 mi; 3 — Bishop, CA — 84 mi; 4 — Blue Eagle Ranch - Currant 12 SSW, NV — 90 mi; 5 — Lee Vining, CA — 111 mi.CA50 mi · 80 km1. Smoky Valley - Carvers, NV — 51 mi12. Dyer, NV — 58 mi23. Bishop, CA — 84 mi34. Blue Eagle Ranch - Currant 12 SSW, NV — 90 mi45. Lee Vining, CA — 111 mi5
  1. Smoky Valley - Carvers, NV 51 mi (82 km)
  2. Dyer, NV 58 mi (94 km)
  3. Bishop, CA 84 mi (135 km)
  4. Blue Eagle Ranch - Currant 12 SSW, NV 90 mi (145 km)
  5. Lee Vining, CA 111 mi (178 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: 38.0511, -117.0903.