U.S. Frost Dates by Weather Station

NOAA station USC00233601 · Missouri

Frost Dates for Hannibal, MO

NOAA weather station Hannibal Water Works (USC00233601), Missouri · elevation 712 ft (217 m) · hardiness zone 6a*

  • Lower-risk planting dateafter April 25only 1 spring in 10 still has a frost later
  • Typical last frostApril 1050% chance of a frost after it
  • Typical first fall frostOctober 2750% chance of a frost before it
  • Frost-free season199 daystypical year, 32°F
  • Hardiness zone6acalculated*

The year at a glance

Frost season at Hannibal, MOSpring: a frost after March 28 in 9 years out of 10, after April 10 in half of the years, after April 25 in 1 year out of 10. Fall: the first frost comes before October 14 in 1 year out of 10, before October 27 in half of the years, before November 9 in 9 years out of 10. Typical frost-free season: 199 days.JanFebMarAprMayJunJulAugSepOctNovDecLast frost ~Apr 10First frost ~Oct 27Frost season at Hannibal, MOSpring: a frost after March 28 in 9 years out of 10, after April 10 in half of the years, after April 25 in 1 year out of 10. Fall: the first frost comes before October 14 in 1 year out of 10, before October 27 in half of the years, before November 9 in 9 years out of 10. Typical frost-free season: 199 days.JFMAMJJASONDLast frost ~Apr 10First frost ~Oct 27
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 30 years of NOAA records (1991–2020 normals)
ChanceLast frost in spring afterFirst frost in fall before
10% (unlikely)April 25October 14
50% (typical)April 10October 27
90% (likely)March 28November 9
Frost-free season (32°F, 50% chance)
199 days
Hard frost (28°F), last in spring, 50% chance after
March 31
Hard frost (28°F), first in fall, 50% chance before
November 5

The last 15 years (2006–2020 normals)

Typical last frost April 9 (1 day earlier than the 30-year normal), typical first fall frost October 29 (2 days later). Frost-free season 202 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 Hannibal: chance of a frost after this dateSpring, chance of a frost after the date: 10% April 25, 20% April 21, 30% April 17, 40% April 13, 50% April 10, 60% April 7, 70% April 4, 80% April 2, 90% March 28. Observed last spring frost in recent years: 2021 April 22, 2022 April 20, 2023 April 7, 2024 March 28, 2025 April 9, 2026 March 29.Spring: last frostChance of a frost after this date10%50%90%Apr 1May 1Apr 25Apr 10Mar 282021: April 222022: April 202023: April 72024: March 282025: April 92026: March 29Fall at Hannibal: chance of a frost before this dateFall, chance of a frost before the date: 10% October 14, 20% October 19, 30% October 22, 40% October 25, 50% October 27, 60% October 30, 70% November 1, 80% November 4, 90% November 9. Observed first fall frost in recent years: 2021 November 2, 2022 October 18, 2023 October 30, 2024 November 23, 2025 November 2.Fall: first frostChance of a frost before this date10%50%90%Oct 1Nov 1Oct 14Oct 27Nov 92021: November 22022: October 182023: October 302024: November 232025: 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 22November 2
2022April 20October 18
2023April 7October 30
2024March 28November 23
2025April 9November 2
2026March 29season not over yet

What these dates mean

October 14 marks the cautious fall date for finishing the harvest in Hannibal, offering only a 10 % chance that a light frost has arrived earlier. Gardeners aiming to pull in tender crops can plan to finish harvest by this date to keep risk low.

The 50% date is April 10, which means there is a 50 % chance of a light frost later than this date, while the 50% date is October 27, meaning a 50 % chance of a light frost earlier than this date. For a cautious spring schedule, the April 25 date carries a 10 % chance of frost later, making it the preferred day to set out tender crops, whereas October 14 serves the same purpose in fall. Hard frosts at 28°F are more damaging than light frosts at 32°F, so the median hard-frost dates of March 31 in spring and November 5 in fall are important reference points.

How to read the probabilities

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

  • Spring: "10% after April 25" 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 14" 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 Hannibal, MONumbered nearest stations: 1 — Saverton Lock and Dam 22, MO — 9 mi; 2 — Quincy Dam 21, IL — 13 mi; 3 — Quincy, IL — 18 mi; 4 — Vandalia, MO — 29 mi; 5 — near Canton, MO — 30 mi.MOIL25 mi · 40 km1. Saverton Lock and Dam 22, MO — 9 mi12. Quincy Dam 21, IL — 13 mi23. Quincy, IL — 18 mi34. Vandalia, MO — 29 mi45. near Canton, MO — 30 mi5
  1. Saverton Lock and Dam 22, MO 9 mi (14 km)
  2. Quincy Dam 21, IL 13 mi (21 km)
  3. Quincy, IL 18 mi (28 km)
  4. Vandalia, MO 29 mi (47 km)
  5. near Canton, MO 30 mi (48 km)

Sources

* Hardiness zone 6a: zone derived from PRISM 2023 grid at the station location (not the official USDA map). Source data: PRISM Group, Oregon State University.

Station coordinates: 39.7231, -91.3747.