U.S. Frost Dates by Weather Station

NOAA station USW00013968 · Oklahoma

Frost Dates for Tulsa, OK

NOAA weather station Tulsa International Airport (USW00013968), Oklahoma · elevation 650 ft (198 m) · hardiness zone 7b*

  • Lower-risk planting dateafter April 15only 1 spring in 10 still has a frost later
  • Typical last frostMarch 3150% chance of a frost after it
  • Typical first fall frostNovember 450% chance of a frost before it
  • Frost-free season220 daystypical year, 32°F
  • Hardiness zone7bcalculated*

The year at a glance

Frost season at Tulsa, OKSpring: a frost after March 11 in 9 years out of 10, after March 31 in half of the years, after April 15 in 1 year out of 10. Fall: the first frost comes before October 20 in 1 year out of 10, before November 4 in half of the years, before November 19 in 9 years out of 10. Typical frost-free season: 220 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Mar 31First frost ~Nov 4Frost season at Tulsa, OKSpring: a frost after March 11 in 9 years out of 10, after March 31 in half of the years, after April 15 in 1 year out of 10. Fall: the first frost comes before October 20 in 1 year out of 10, before November 4 in half of the years, before November 19 in 9 years out of 10. Typical frost-free season: 220 days.JFMAMJJASONDLast frost ~Mar 31First frost ~Nov 4
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 29 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 15October 20
50% (typical)March 31November 4
90% (likely)March 11November 19
Frost-free season (32°F, 50% chance)
220 days
Hard frost (28°F), last in spring, 50% chance after
March 17
Hard frost (28°F), first in fall, 50% chance before
November 13

The last 15 years (2006–2020 normals)

Typical last frost March 31 (same as the 30-year normal), typical first fall frost November 2 (2 days earlier). Frost-free season 218 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 Tulsa: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 15, 20% April 9, 30% April 5, 40% April 2, 50% March 31, 60% March 27, 70% March 23, 80% March 18, 90% March 11. Observed last spring frost in recent years: 2021 April 21, 2022 April 9, 2023 March 27, 2024 March 28, 2025 April 7, 2026 March 17.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1Apr 15Mar 31Mar 112021: April 212022: April 92023: March 272024: March 282025: April 72026: March 17Fall at Tulsa: chance of a frost before this dateFall, chance of a frost before the date: 10% October 20, 20% October 26, 30% October 30, 40% November 1, 50% November 4, 60% November 6, 70% November 9, 80% November 12, 90% November 19. Observed first fall frost in recent years: 2021 November 13, 2022 October 18, 2023 October 30, 2024 November 22, 2025 November 2.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 20Nov 4Nov 192021: November 132022: October 182023: October 302024: November 222025: November 2
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 21November 13
2022April 9October 18
2023March 27October 30
2024March 28November 22
2025April 7November 2
2026March 17season not over yet

What these dates mean

October 20 is the cautious fall date for finishing the harvest of tender crops in Tulsa, as only a 10 % chance of a light frost exists before that day. Gardeners can therefore schedule their late-season harvests to conclude by that date to keep risk low.

The median 32 °F dates are March 31 in spring and November 4 in fall; they represent a 50 % chance of a light frost occurring later (spring) or earlier (fall). For a low-risk plan in spring, the cautious date is April 15, when the chance of a light frost later drops to 10 %; planting before the March 11 gamble date carries a 90 % chance of frost. In fall, the cautious date is October 20, providing a similar 10 % chance of frost earlier than that day.

Hard frost at 28 °F, marked by the median dates March 17 and November 13, can damage plants that survive a light frost, making it a more serious concern for tender crops.

How to read the probabilities

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

  • Spring: "10% after April 15" 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 20" 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 Tulsa, OKNumbered nearest stations: 1 — Claremore, OK — 19 mi; 2 — near Bartlesville, OK — 40 mi; 3 — Ralston, OK — 52 mi; 4 — Sedan, KS — 66 mi; 5 — Independence, KS — 72 mi.OK25 mi · 40 km1. Claremore, OK — 19 mi12. near Bartlesville, OK — 40 mi23. Ralston, OK — 52 mi34. Sedan, KS — 66 mi45. Independence, KS — 72 mi5
  1. Claremore, OK 19 mi (31 km)
  2. near Bartlesville, OK 40 mi (64 km)
  3. Ralston, OK 52 mi (84 km)
  4. Sedan, KS 66 mi (107 km)
  5. Independence, KS 72 mi (117 km)

Sources

* Hardiness zone 7b: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 36.1994, -95.8872.