U.S. Frost Dates by Weather Station

NOAA station USC00396574 · South Dakota

Frost Dates for Pickstown, SD

NOAA weather station Pickstown (USC00396574), South Dakota · elevation 1490 ft (454 m) · hardiness zone 5b*

  • Lower-risk planting dateafter May 12only 1 spring in 10 still has a frost later
  • Typical last frostApril 3050% chance of a frost after it
  • Typical first fall frostOctober 1350% chance of a frost before it
  • Frost-free season165 daystypical year, 32°F
  • Hardiness zone5bcalculated*

The year at a glance

Frost season at Pickstown, SDSpring: a frost after April 17 in 9 years out of 10, after April 30 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 13 in half of the years, before October 25 in 9 years out of 10. Typical frost-free season: 165 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 30First frost ~Oct 13Frost season at Pickstown, SDSpring: a frost after April 17 in 9 years out of 10, after April 30 in half of the years, after May 12 in 1 year out of 10. Fall: the first frost comes before September 29 in 1 year out of 10, before October 13 in half of the years, before October 25 in 9 years out of 10. Typical frost-free season: 165 days.JFMAMJJASONDLast frost ~Apr 30First frost ~Oct 13
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 26 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)May 12September 29
50% (typical)April 30October 13
90% (likely)April 17October 25
Frost-free season (32°F, 50% chance)
165 days
Hard frost (28°F), last in spring, 50% chance after
April 20
Hard frost (28°F), first in fall, 50% chance before
October 22

The last 15 years (2006–2020 normals)

Typical last frost May 2 (2 days later than the 30-year normal), typical first fall frost October 15 (2 days later). Frost-free season 166 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 Pickstown: chance of a frost after this dateSpring, chance of a frost after the date: 10% May 12, 20% May 7, 30% May 5, 40% May 2, 50% April 30, 60% April 28, 70% April 25, 80% April 22, 90% April 17.Spring: last frostChance of a frost after this date10%50%90%May 1May 12Apr 30Apr 17Fall at Pickstown: chance of a frost before this dateFall, chance of a frost before the date: 10% September 29, 20% October 4, 30% October 7, 40% October 10, 50% October 13, 60% October 15, 70% October 18, 80% October 21, 90% October 25.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Sep 29Oct 13Oct 25
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

May 12 is the cautious spring date for Pickstown; with only a 10 % chance of a light frost after that day, a gardener can plan to set out tender crops with minimal risk. The comparable cautious fall date is September 29, when there is only a 10 % chance that a light frost has arrived earlier, indicating a reasonable window to finish harvesting tender crops.

The 50 % dates mark the median point where a light frost is equally likely to have occurred or not. In spring the 50 % date is April 30 and in fall it is October 13; these dates do not represent frost events but show where odds balance. The hard-frost 50 % dates are April 20 and October 22, and a hard frost at 28 °F can injure plants that would survive a light frost at 32 °F, making it a more serious threat.

How to read the probabilities

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

  • Spring: "10% after May 12" 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 29" 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 Pickstown, SDNumbered nearest stations: 1 — Lynch, NE — 17 mi; 2 — Butte, NE — 19 mi; 3 — Tyndall, SD — 34 mi; 4 — Academy, SD — 39 mi; 5 — O'Neill, NE — 43 mi.SD25 mi · 40 km1. Lynch, NE — 17 mi12. Butte, NE — 19 mi23. Tyndall, SD — 34 mi34. Academy, SD — 39 mi45. O'Neill, NE — 43 mi5
  1. Lynch, NE 17 mi (27 km)
  2. Butte, NE 19 mi (31 km)
  3. Tyndall, SD 34 mi (55 km)
  4. Academy, SD 39 mi (63 km)
  5. O'Neill, NE 43 mi (69 km)

Sources

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

Station coordinates: 43.0689, -98.5325.