U.S. Frost Dates by Weather Station

NOAA station USC00420738 · Utah

Frost Dates for Blanding, UT

NOAA weather station Blanding (USC00420738), Utah · elevation 6032 ft (1839 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 16only 1 spring in 10 still has a frost later
  • Typical last frostApril 2850% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Blanding, UTSpring: a frost after April 13 in 9 years out of 10, after April 28 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 28First frost ~Oct 21Frost season at Blanding, UTSpring: a frost after April 13 in 9 years out of 10, after April 28 in half of the years, after May 16 in 1 year out of 10. Fall: the first frost comes before October 6 in 1 year out of 10, before October 21 in half of the years, before November 6 in 9 years out of 10. Typical frost-free season: 174 days.JFMAMJJASONDLast frost ~Apr 28First frost ~Oct 21
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 16October 6
50% (typical)April 28October 21
90% (likely)April 13November 6
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 14
Hard frost (28°F), first in fall, 50% chance before
November 1

The last 15 years (2006–2020 normals)

Typical last frost April 28 (same as the 30-year normal), typical first fall frost October 20 (1 day earlier). Frost-free season 173 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 Blanding: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 16, 20% May 8, 30% May 3, 40% April 30, 50% April 28, 60% April 25, 70% April 21, 80% April 18, 90% April 13. Observed last spring frost in recent years: 2021 April 17.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 16Apr 28Apr 132021: April 17Fall at Blanding: chance of a frost before this dateFall, chance of a frost before the date: 10% October 6, 20% October 10, 30% October 14, 40% October 18, 50% October 21, 60% October 24, 70% October 28, 80% November 1, 90% November 6. Observed first fall frost in recent years: 2021 October 12.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 6Oct 21Nov 62021: 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 17October 12
2022incomplete recordincomplete record
2023incomplete recordincomplete record
2024incomplete recordincomplete record
2025incomplete recordincomplete record
2026incomplete recordseason not over yet

What these dates mean

The 174 days between the 50% dates in Blanding — April 28 and October 21 — define the span in which a light frost is equally likely to occur or not.

For a gardener, the 50% dates are the midpoint of frost risk, meaning there is a 50 % chance of a light frost on each of those days. The cautious spring date for setting out tender crops is May 16, when the chance of a later frost is only 10 %; planting on April 13 carries a 90 % gamble. In the fall the cautious date to finish harvesting tender crops is October 6, with a 10 % chance that a frost has already arrived; waiting until November 6 would be a 90 % gamble.

A hard frost at 28 °F (April 14 in spring, November 1 in fall) can injure plants that survive a light frost at 32 °F, so it is a more critical threshold.

How to read the probabilities

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

  • Spring: "10% after May 16" 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 6" 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 Blanding, UTNumbered nearest stations: 1 — Bluff, UT — 23 mi; 2 — Natural Bridges National Monument, UT — 27 mi; 3 — Canyonlands-The Needles, UT — 41 mi; 4 — Cortez, CO — 52 mi; 5 — Hans Flat Ranger Station, UT — 58 mi.UTCO25 mi · 40 km1. Bluff, UT — 23 mi12. Natural Bridges National Monument, UT — 27 mi23. Canyonlands-The Needles, UT — 41 mi34. Cortez, CO — 52 mi45. Hans Flat Ranger Station, UT — 58 mi5
  1. Bluff, UT 23 mi (37 km)
  2. Natural Bridges National Monument, UT 27 mi (43 km)
  3. Canyonlands-The Needles, UT 41 mi (66 km)
  4. Cortez, CO 52 mi (84 km)
  5. Hans Flat Ranger Station, UT 58 mi (94 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: 37.6131, -109.4847.