U.S. Frost Dates by Weather Station

NOAA station USC00428119 · Utah

Frost Dates for Spanish Fork, UT

NOAA weather station Spanish Fork Power House (USC00428119), Utah · elevation 4720 ft (1439 m) · hardiness zone 7a*

  • Lower-risk planting dateafter May 13only 1 spring in 10 still has a frost later
  • Typical last frostApril 2550% chance of a frost after it
  • Typical first fall frostOctober 1850% chance of a frost before it
  • Frost-free season174 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season at Spanish Fork, UTSpring: a frost after April 10 in 9 years out of 10, after April 25 in half of the years, after May 13 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: 174 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 25First frost ~Oct 18Frost season at Spanish Fork, UTSpring: a frost after April 10 in 9 years out of 10, after April 25 in half of the years, after May 13 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: 174 days.JFMAMJJASONDLast frost ~Apr 25First 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 13October 4
50% (typical)April 25October 18
90% (likely)April 10November 1
Frost-free season (32°F, 50% chance)
174 days
Hard frost (28°F), last in spring, 50% chance after
April 9
Hard frost (28°F), first in fall, 50% chance before
October 30

The last 15 years (2006–2020 normals)

Typical last frost April 27 (2 days later than the 30-year normal), typical first fall frost October 17 (1 day earlier). Frost-free season 171 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 Spanish Fork: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 13, 20% May 5, 30% May 2, 40% April 29, 50% April 25, 60% April 21, 70% April 18, 80% April 14, 90% April 10. Observed last spring frost in recent years: 2021 April 12, 2022 May 21, 2023 April 21, 2024 May 8, 2025 April 19, 2026 April 18.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1May 13Apr 25Apr 102021: April 122022: May 212023: April 212024: May 82025: April 192026: April 18Fall at Spanish Fork: 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 21, 70% October 23, 80% October 27, 90% November 1. Observed first fall frost in recent years: 2021 October 13, 2022 October 23, 2023 October 27, 2024 October 30, 2025 October 21.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 4Oct 18Nov 12021: October 132022: October 232023: October 272024: October 302025: October 21
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 12October 13
2022May 21October 23
2023April 21October 27
2024May 8October 30
2025April 19October 21
2026April 18season not over yet

What these dates mean

May 13 is the cautious spring light-frost date for Spanish Fork; with only a 10 % chance of a frost later, it lets a gardener plan to set out tender crops with minimal risk. The 90 % chance date of April 10 is a gamble, while the median date of April 25 marks a 50 % chance of a frost later than that day.

In fall, October 4 is the cautious light-frost date, giving a 10 % chance of a frost earlier and allowing a gardener to finish harvesting tender crops. The median fall date is October 18, which carries a 50 % chance of a frost earlier. For hard frost, the 50 % dates are April 9 in spring and October 30 in fall; a hard frost at 28 °F can damage plants that survive a light frost at 32 °F, making its timing more critical.

How to read the probabilities

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

  • Spring: "10% after May 13" 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 Spanish Fork, UTNumbered nearest stations: 1 — near Provo, UT — 12 mi; 2 — near Santaquin, UT — 13 mi; 3 — Pleasant Grove, UT — 21 mi; 4 — near Midway, UT — 23 mi; 5 — Nephi, UT — 28 mi.25 mi · 40 km1. near Provo, UT — 12 mi12. near Santaquin, UT — 13 mi23. Pleasant Grove, UT — 21 mi34. near Midway, UT — 23 mi45. Nephi, UT — 28 mi5
  1. near Provo, UT 12 mi (19 km)
  2. near Santaquin, UT 13 mi (20 km)
  3. Pleasant Grove, UT 21 mi (34 km)
  4. near Midway, UT 23 mi (37 km)
  5. Nephi, UT 28 mi (45 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: 40.08, -111.6047.