U.S. Frost Dates by Weather Station

NOAA station USC00340830 · Oklahoma

Frost Dates for Blanchard, OK

NOAA weather station Blanchard 2 SSW (USC00340830), Oklahoma · elevation 1275 ft (389 m) · hardiness zone 7b*

  • Lower-risk planting dateafter April 19only 1 spring in 10 still has a frost later
  • Typical last frostApril 350% chance of a frost after it
  • Typical first fall frostNovember 450% chance of a frost before it
  • Frost-free season214 daystypical year, 32°F
  • Hardiness zone7bcalculated*

The year at a glance

Frost season at Blanchard, OKSpring: a frost after March 15 in 9 years out of 10, after April 3 in half of the years, after April 19 in 1 year out of 10. Fall: the first frost comes before October 21 in 1 year out of 10, before November 4 in half of the years, before November 18 in 9 years out of 10. Typical frost-free season: 214 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 3First frost ~Nov 4Frost season at Blanchard, OKSpring: a frost after March 15 in 9 years out of 10, after April 3 in half of the years, after April 19 in 1 year out of 10. Fall: the first frost comes before October 21 in 1 year out of 10, before November 4 in half of the years, before November 18 in 9 years out of 10. Typical frost-free season: 214 days.JFMAMJJASONDLast frost ~Apr 3First 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 28 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 19October 21
50% (typical)April 3November 4
90% (likely)March 15November 18
Frost-free season (32°F, 50% chance)
214 days
Hard frost (28°F), last in spring, 50% chance after
March 22
Hard frost (28°F), first in fall, 50% chance before
November 13

The last 15 years (2006–2020 normals)

Typical last frost March 31 (3 days earlier than the 30-year normal), typical first fall frost November 4. 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 Blanchard: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 19, 20% April 14, 30% April 9, 40% April 6, 50% April 3, 60% March 31, 70% March 27, 80% March 22, 90% March 15.Spring: last frostChance of a frost after this date10%50%90%Mar 1Apr 1May 1Apr 19Apr 3Mar 15Fall at Blanchard: chance of a frost before this dateFall, chance of a frost before the date: 10% October 21, 20% October 26, 30% October 30, 40% November 1, 50% November 4, 60% November 7, 70% November 10, 80% November 13, 90% November 18.Fall: first frostChance of a frost before this date10%50%90%Nov 1Dec 1Oct 21Nov 4Nov 18
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.

What these dates mean

Setting tender crops on the early spring date of March 15 in Blanchard carries a 90 % chance of encountering a light frost later, so planting then is a gamble. The cautious spring date of April 19 reduces that risk to a 10 % chance, giving growers a lower-risk window for starting more tender varieties.

For a gardener, the 50 % date of April 3 marks the point at which a light frost is equally likely to occur later, while the 50 % date of November 4 marks the point at which a light frost is equally likely to have occurred earlier. The cautious fall date of October 21 limits the chance of an early frost to 10 %. A hard frost, recorded at 28 °F, is more consequential than a light frost because it can damage plant tissue that survives the milder 32 °F threshold; the median hard-frost dates are March 22 and November 13.

How to read the probabilities

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

  • Spring: "10% after April 19" 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 21" 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 Blanchard, OKNumbered nearest stations: 1 — near Oklahoma City, OK — 19 mi; 2 — Meeker, OK — 47 mi; 3 — Seminole, OK — 58 mi; 4 — Healdton, OK — 63 mi; 5 — Watonga, OK — 66 mi.50 mi · 80 km1. near Oklahoma City, OK — 19 mi12. Meeker, OK — 47 mi23. Seminole, OK — 58 mi34. Healdton, OK — 63 mi45. Watonga, OK — 66 mi5
  1. near Oklahoma City, OK 19 mi (31 km)
  2. Meeker, OK 47 mi (76 km)
  3. Seminole, OK 58 mi (93 km)
  4. Healdton, OK 63 mi (101 km)
  5. Watonga, OK 66 mi (106 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: 35.1183, -97.67.