U.S. Frost Dates by Weather Station

NOAA station USW00003959 · Oklahoma

Frost Dates near Bartlesville, OK

NOAA weather station Bartlesville F P Field (USW00003959), Oklahoma · elevation 715 ft (218 m) · hardiness zone 7a*

Bartlesville is the nearest town to the station (2.9 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 April 28only 1 spring in 10 still has a frost later
  • Typical last frostApril 1250% chance of a frost after it
  • Typical first fall frostOctober 2150% chance of a frost before it
  • Frost-free season192 daystypical year, 32°F
  • Hardiness zone7acalculated*

The year at a glance

Frost season near Bartlesville, OKSpring: a frost after March 28 in 9 years out of 10, after April 12 in half of the years, after April 28 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 21 in half of the years, before November 3 in 9 years out of 10. Typical frost-free season: 192 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 12First frost ~Oct 21Frost season near Bartlesville, OKSpring: a frost after March 28 in 9 years out of 10, after April 12 in half of the years, after April 28 in 1 year out of 10. Fall: the first frost comes before October 5 in 1 year out of 10, before October 21 in half of the years, before November 3 in 9 years out of 10. Typical frost-free season: 192 days.JFMAMJJASONDLast frost ~Apr 12First 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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 28October 5
50% (typical)April 12October 21
90% (likely)March 28November 3
Frost-free season (32°F, 50% chance)
192 days
Hard frost (28°F), last in spring, 50% chance after
March 31
Hard frost (28°F), first in fall, 50% chance before
October 31

The last 15 years (2006–2020 normals)

Typical last frost April 12 (same as the 30-year normal), typical first fall frost October 23 (2 days later). Frost-free season 194 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 Bartlesville: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 28, 20% April 23, 30% April 18, 40% April 15, 50% April 12, 60% April 9, 70% April 6, 80% April 2, 90% March 28. Observed last spring frost in recent years: 2021 April 22, 2022 April 19, 2023 May 3, 2024 April 22, 2025 April 8, 2026 March 28.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 28Apr 12Mar 282021: April 222022: April 192023: May 32024: April 222025: April 82026: March 28Fall near Bartlesville: chance of a frost before this dateFall, chance of a frost before the date: 10% October 5, 20% October 11, 30% October 15, 40% October 19, 50% October 21, 60% October 24, 70% October 27, 80% October 30, 90% November 3. Observed first fall frost in recent years: 2021 October 30, 2022 October 18, 2023 October 17, 2024 October 16, 2025 November 1.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 5Oct 21Nov 32021: October 302022: October 182023: October 172024: October 162025: November 1
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 22October 30
2022April 19October 18
2023May 3October 17
2024April 22October 16
2025April 8November 1
2026March 28season not over yet

What these dates mean

October 5 marks the cautious fall date for the Bartlesville area, indicating a 10 % chance that a light frost has already arrived and signaling the latest time to finish harvesting tender crops. In spring the cautious date is April 28, when only a 10 % chance remains that a light frost will occur later, while planting before March 28 carries a 90 % risk and is a gamble.

The 50% dates—April 12 for spring and October 21 for fall—show the point at which the probability of a light frost is exactly even; a gardener can view them as the median odds for frost occurrence. The hard-frost median dates are March 31 and October 31, separate from the light-frost calendar.

A hard frost at 28 °F can damage plant tissue that survives a 32 °F light frost, so it represents a greater threat to 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 28" 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 5" 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 Bartlesville, OKNumbered nearest stations: 1 — Sedan, KS — 27 mi; 2 — Independence, KS — 37 mi; 3 — Claremore, OK — 39 mi; 4 — Tulsa, OK — 40 mi; 5 — Mound Valley, KS — 43 mi.OKMOAR25 mi · 40 km1. Sedan, KS — 27 mi12. Independence, KS — 37 mi23. Claremore, OK — 39 mi34. Tulsa, OK — 40 mi45. Mound Valley, KS — 43 mi5
  1. Sedan, KS 27 mi (43 km)
  2. Independence, KS 37 mi (60 km)
  3. Claremore, OK 39 mi (64 km)
  4. Tulsa, OK 40 mi (64 km)
  5. Mound Valley, KS 43 mi (69 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: 36.7683, -96.0261.