U.S. Frost Dates by Weather Station

NOAA station USC00267697 · Nevada

Frost Dates for Sparks, NV

NOAA weather station Sparks (USC00267697), Nevada · elevation 4357 ft (1328 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 25only 1 spring in 10 still has a frost later
  • Typical last frostMay 150% chance of a frost after it
  • Typical first fall frostOctober 1050% chance of a frost before it
  • Frost-free season160 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Sparks, NVSpring: a frost after April 17 in 9 years out of 10, after May 1 in half of the years, after May 25 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 10 in half of the years, before October 24 in 9 years out of 10. Typical frost-free season: 160 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 1First frost ~Oct 10Frost season at Sparks, NVSpring: a frost after April 17 in 9 years out of 10, after May 1 in half of the years, after May 25 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 10 in half of the years, before October 24 in 9 years out of 10. Typical frost-free season: 160 days.JFMAMJJASONDLast frost ~May 1First frost ~Oct 10
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)May 25September 29
50% (typical)May 1October 10
90% (likely)April 17October 24
Frost-free season (32°F, 50% chance)
160 days
Hard frost (28°F), last in spring, 50% chance after
April 16
Hard frost (28°F), first in fall, 50% chance before
October 23

The last 15 years (2006–2020 normals)

Typical last frost May 5 (4 days later than the 30-year normal), typical first fall frost October 12 (2 days later). Frost-free season 158 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 Sparks: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 25, 20% May 14, 30% May 8, 40% May 4, 50% May 1, 60% April 29, 70% April 26, 80% April 22, 90% April 17. Observed last spring frost in recent years: 2021 April 28.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1May 25May 1Apr 172021: April 28Fall at Sparks: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 3, 30% October 5, 40% October 8, 50% October 10, 60% October 13, 70% October 16, 80% October 19, 90% October 24. Observed first fall frost in recent years: 2021 October 12.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 10Oct 242021: October 12
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 12
2022no datano data
2023no datano data
2024no datano data
2025no datano data
2026no dataseason not over yet

What these dates mean

September 29 is the cautious fall date for finishing the harvest of tender crops in Sparks, with only a 10 % chance that a light frost has arrived earlier. The 50 % light-frost date for fall is October 10, meaning an equal chance of frost having occurred before or after that day. The 90 % gamble date of October 24 indicates a high likelihood that frost is already present. The hard-frost median for fall occurs on October 23; a 28 °F frost can injure plants that tolerate the 32 °F light frost.

The cautious spring date for setting out tender crops is May 25, when the chance of a later light frost is only 10 %. The 50 % light-frost date is May 1, marking an even chance of frost occurring after that point, while April 17 carries a 90 % chance of frost later, making it a gamble. Hard-frost medians are April 16 in spring, and hard frost matters more because a 28 °F event can damage plants that survive a 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 May 25" 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 29" 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 Sparks, NVNumbered nearest stations: 1 — near Reno, NV — 5 mi; 2 — Virginia City, NV — 17 mi; 3 — Tahoe City, CA — 35 mi; 4 — Minden, NV — 42 mi; 5 — Portola, CA — 43 mi.CANV25 mi · 40 km1. near Reno, NV — 5 mi12. Virginia City, NV — 17 mi23. Tahoe City, CA — 35 mi34. Minden, NV — 42 mi45. Portola, CA — 43 mi5
  1. near Reno, NV 5 mi (9 km)
  2. Virginia City, NV 17 mi (28 km)
  3. Tahoe City, CA 35 mi (56 km)
  4. Minden, NV 42 mi (67 km)
  5. Portola, CA 43 mi (69 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: 39.5558, -119.7333.