U.S. Frost Dates by Weather Station

NOAA station USC00044881 · California

Frost Dates for Lee Vining, CA

NOAA weather station Lee Vining (USC00044881), California · elevation 6797 ft (2072 m) · hardiness zone 7a*

  • Lower-risk planting dateafter June 9only 1 spring in 10 still has a frost later
  • Typical last frostMay 2350% chance of a frost after it
  • Typical first fall frostOctober 950% chance of a frost before it
  • Frost-free season139 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Lee Vining, CASpring: a frost after May 2 in 9 years out of 10, after May 23 in half of the years, after June 9 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 9 in half of the years, before October 24 in 9 years out of 10. Typical frost-free season: 139 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 23First frost ~Oct 9Frost season at Lee Vining, CASpring: a frost after May 2 in 9 years out of 10, after May 23 in half of the years, after June 9 in 1 year out of 10. Fall: the first frost comes before September 27 in 1 year out of 10, before October 9 in half of the years, before October 24 in 9 years out of 10. Typical frost-free season: 139 days.JFMAMJJASONDLast frost ~May 23First frost ~Oct 9
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)June 9September 27
50% (typical)May 23October 9
90% (likely)May 2October 24
Frost-free season (32°F, 50% chance)
139 days
Hard frost (28°F), last in spring, 50% chance after
May 2
Hard frost (28°F), first in fall, 50% chance before
October 21

The last 15 years (2006–2020 normals)

Typical last frost May 24 (1 day later than the 30-year normal), typical first fall frost October 5 (4 days earlier). Frost-free season 134 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 Lee Vining: chance of a frost after this dateSpring, chance of a frost after the date: 10% June 9, 20% June 3, 30% May 31, 40% May 27, 50% May 23, 60% May 18, 70% May 14, 80% May 8, 90% May 2. Observed last spring frost in recent years: 2021 May 22, 2022 May 21, 2023 May 10, 2024 May 10, 2025 May 14, 2026 May 27.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 9May 23May 22021: May 222022: May 212023: May 102024: May 102025: May 142026: May 27Fall at Lee Vining: chance of a frost before this dateFall, chance of a frost before the date: 10% September 27, 20% October 1, 30% October 4, 40% October 6, 50% October 9, 60% October 13, 70% October 16, 80% October 19, 90% October 24. Observed first fall frost in recent years: 2021 September 29, 2022 October 23, 2023 October 12, 2024 September 13, 2025 October 12.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 27Oct 9Oct 242021: September 292022: October 232023: October 122024: September 132025: 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
2021May 22September 29
2022May 21October 23
2023May 10October 12
2024May 10September 13
2025May 14October 12
2026May 27season not over yet

What these dates mean

September 27 is the cautious fall date for finishing the harvest of tender crops in Lee Vining, reflecting a 10 % chance that a light frost has arrived earlier. In spring the comparable cautious date is June 9, when there is only a 10 % chance of a light frost occurring later, making it the lower-risk day to set out tender crops.

Gardeners can use the 50 % dates—May 23 for spring and October 9 for fall—to understand that the odds of a light frost are equal on either side of those days. By contrast, the 90 % chance dates—May 2 in spring and October 24 in fall—are considered risky times for tender crops. The 50 % hard-frost dates are May 2 and October 21; a hard frost at 28 °F can damage plants more severely than a light frost at 32 °F, so it is an important threshold to watch.

How to read the probabilities

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

  • Spring: "10% after June 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 September 27" 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 Lee Vining, CANumbered nearest stations: 1 — Cherry Valley Dam, CA — 43 mi; 2 — Bishop, CA — 58 mi; 3 — Auberry, CA — 64 mi; 4 — Smith, NV — 65 mi; 5 — Dyer, NV — 66 mi.CANV50 mi · 80 km1. Cherry Valley Dam, CA — 43 mi12. Bishop, CA — 58 mi23. Auberry, CA — 64 mi34. Smith, NV — 65 mi45. Dyer, NV — 66 mi5
  1. Cherry Valley Dam, CA 43 mi (70 km)
  2. Bishop, CA 58 mi (93 km)
  3. Auberry, CA 64 mi (102 km)
  4. Smith, NV 65 mi (105 km)
  5. Dyer, NV 66 mi (106 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: 37.9567, -119.1194.