U.S. Frost Dates by Weather Station

NOAA station USC00427395 · Utah

Frost Dates near Roosevelt, UT

NOAA weather station Roosevelt Radio (USC00427395), Utah · elevation 5014 ft (1528 m) · hardiness zone 5a*

Roosevelt is the nearest town to the station (1.8 mi away) in GeoNames (CC BY 4.0). The dates below are measured at the station, not in the town itself.

  • 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 frostSeptember 2250% chance of a frost before it
  • Frost-free season121 daystypical year, 32°F
  • Hardiness zone5acalculated*

The year at a glance

Frost season near Roosevelt, UTSpring: a frost after May 9 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 8 in 1 year out of 10, before September 22 in half of the years, before October 3 in 9 years out of 10. Typical frost-free season: 121 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~May 23First frost ~Sep 22Frost season near Roosevelt, UTSpring: a frost after May 9 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 8 in 1 year out of 10, before September 22 in half of the years, before October 3 in 9 years out of 10. Typical frost-free season: 121 days.JFMAMJJASONDLast frost ~May 23First frost ~Sep 22
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)June 9September 8
50% (typical)May 23September 22
90% (likely)May 9October 3
Frost-free season (32°F, 50% chance)
121 days
Hard frost (28°F), last in spring, 50% chance after
May 8
Hard frost (28°F), first in fall, 50% chance before
October 2

The last 15 years (2006–2020 normals)

Typical last frost May 22 (1 day earlier than the 30-year normal), typical first fall frost September 24 (2 days later). Frost-free season 123 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 near Roosevelt: 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 20, 70% May 17, 80% May 13, 90% May 9. Observed last spring frost in recent years: 2021 May 22, 2022 May 30.Spring: last frostChance of a frost after this date10%50%90%May 1Jun 1Jun 9May 23May 92021: May 222022: May 30Fall near Roosevelt: chance of a frost before this dateFall, chance of a frost before the date: 10% September 8, 20% September 13, 30% September 17, 40% September 19, 50% September 22, 60% September 25, 70% September 27, 80% September 30, 90% October 3. Observed first fall frost in recent years: 2021 September 22, 2022 October 12.Fall: first frostChance of a frost before this date10%50%90%Sep 1Oct 1Sep 8Sep 22Oct 32021: September 222022: 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 22
2022May 30October 12
2023incomplete recordincomplete record
2024incomplete recordincomplete record
2025no datano data
2026no dataseason not over yet

What these dates mean

June 9 marks the cautious spring date for the Roosevelt area, with a 10% chance of a light frost later, giving gardeners a reliable point to set out tender crops.

The median light-frost dates are May 23 in spring and September 22 in fall; each indicates a 50% chance of a frost later than this date in spring and earlier than this date in fall. The cautious fall date is September 8, when there is only a 10% chance a light frost has arrived, while May 9 (90% chance) and October 3 (90% chance) are gambles. The hard-frost 50% dates are May 8 and October 2, and a hard frost at 28°F can damage plants that survive a light frost at 32°F.

With 28 years of record and a span of 121 days between the two 32°F 50% dates, the period for tender crops is clearly bracketed for this station.

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 8" 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 Roosevelt, UTNumbered nearest stations: 1 — Neola, UT — 10 mi; 2 — Ouray, UT — 20 mi; 3 — Duchesne, UT — 25 mi; 4 — Jensen, UT — 33 mi; 5 — Flaming Gorge, UT — 53 mi.UTCOWY25 mi · 40 km1. Neola, UT — 10 mi12. Ouray, UT — 20 mi23. Duchesne, UT — 25 mi34. Jensen, UT — 33 mi45. Flaming Gorge, UT — 53 mi5
  1. Neola, UT 10 mi (16 km)
  2. Ouray, UT 20 mi (32 km)
  3. Duchesne, UT 25 mi (40 km)
  4. Jensen, UT 33 mi (53 km)
  5. Flaming Gorge, UT 53 mi (85 km)

Sources

* Hardiness zone 5a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 40.2878, -109.9586.