USDA Hardiness Zone 6a

Frost Dates for 64633 — Carrollton, Missouri

NOAA 1991–2020 normals from Carrollton, MO (705 ft), under a mile northwest.

Updated October 28, 2026

In Carrollton, the last spring frost (32°F) is around April 16 in half of years and has passed by May 1 in nine years out of ten. The first fall frost comes around October 23, as early as October 7 one year in ten, leaving a typical freeze-free season of 187 days (NOAA, Carrollton, MO).

Last spring frost: April 16
First fall frost: October 23
Growing season: 187 days
Hardiness zone: 6a

First snow: December 9
Last snow: March 1
Winters with snow: 100%
Snow per year: 12.7"

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Frost risk by date in Carrollton

Half of springs at Carrollton, MO see their last 32°F night by April 16; only one in ten is past it by April 1, and one in ten still has one after May 1. Planting tender crops after April 23 leaves a 30% risk of a frost on them, after April 27 20%, and after May 1 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 158 Missouri stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 23 in half of years, as early as October 7 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 9 days later, around November 1; in spring the one-in-ten date for 28°F is April 21, 10 days before the 32°F one. The freeze-free season lasts 187 days in a typical year, shorter than at 73% of the 158 Missouri stations; it reaches 207 days one year in ten and falls short of 166 one year in ten. On average 117 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about April 27, and return around October 12. Severe cold of 16°F or below comes every winter, usually between November 30 and March 6.

Spring: the chance of another night this cold after the date
Low	90%	80%	70%	60%	50%	40%	30%	20%	10%
36°F	Apr 13	Apr 17	Apr 21	Apr 24	Apr 27	Apr 29	May 1	May 5	May 9
32°F	Apr 1	Apr 7	Apr 10	Apr 13	Apr 16	Apr 20	Apr 23	Apr 27	May 1
28°F	Mar 19	Mar 26	Mar 30	Apr 1	Apr 4	Apr 8	Apr 11	Apr 15	Apr 21
24°F	Mar 7	Mar 13	Mar 18	Mar 21	Mar 26	Mar 29	Mar 31	Apr 4	Apr 9
20°F	Feb 27	Mar 3	Mar 7	Mar 10	Mar 14	Mar 17	Mar 21	Mar 26	Mar 31
16°F	Feb 18	Feb 24	Feb 28	Mar 2	Mar 6	Mar 8	Mar 12	Mar 16	Mar 22

Fall: the chance the first night this cold has come by the date
Low	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Sep 28	Oct 2	Oct 6	Oct 9	Oct 12	Oct 15	Oct 17	Oct 21	Oct 25
32°F	Oct 7	Oct 13	Oct 17	Oct 20	Oct 23	Oct 25	Oct 27	Oct 30	Nov 3
28°F	Oct 19	Oct 24	Oct 28	Oct 30	Nov 1	Nov 3	Nov 6	Nov 9	Nov 14
24°F	Oct 31	Nov 1	Nov 5	Nov 7	Nov 9	Nov 12	Nov 16	Nov 20	Nov 26
20°F	Nov 6	Nov 10	Nov 13	Nov 17	Nov 20	Nov 24	Nov 28	Dec 1	Dec 7
16°F	Nov 11	Nov 17	Nov 23	Nov 27	Nov 30	Dec 4	Dec 8	Dec 12	Dec 18

Freeze probabilities 1991–2020 at Carrollton, MO, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.

Frost risk on any date in 64633 →Compare Carrollton with another place →

Frost risk through the year in Carrollton

Frost curve for Carrollton, Missouri (Carrollton, MO, NOAA 1991–2020): the chance of another 32°F night falls from 90% on April 1 to 50% on April 16 and 10% on May 1; the chance that the first fall one has come rises from 10% on October 7 to 50% on October 23 and 90% on November 3. — In Carrollton, the spring curve drops under 10% on May 1 and the fall curve passes 10% on October 7, 159 days later; that gap is shorter than at 68% of the 158 Missouri stations with frost dates. The spring risk falls from 90% to 10% over 30 days (April 1 to May 1) and the fall risk climbs from 10% to 90% over 27 days (October 7 to November 3): both ends of the season vary about as much. At Marshall, MO, 21 miles southeast, the same gap runs from April 27 to October 12, 9 days longer.

Chance of a frost after each planting date in Carrollton
Planted on	Another 32°F night	28°F night
Apr 2	88%	57%
Apr 9	73%	37%
Apr 1650% date	50%	18%
Apr 23	30%	under 10%
Apr 30	13%	under 10%
May 7	under 10%	under 10%

Weather by month in Carrollton

July is the warmest month at Carrollton, MO, averaging 88°F by day and 67°F at night; January is the coldest at 37°F and 17°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 11% of years.

Warmth for growing adds up to 3,838 growing degree days a year (base 50°F), fewer than at 74% of the 158 Missouri stations. 36% of them (1,387) have built up by the end of June, and July adds the most, 852. Precipitation totals 40.2 inches a year, most in June (5.4") and least in January (1.4"); May to September bring 58% of it.

Monthly normals 1991–2020 at Carrollton, MO
Month	High °F	Low °F	Precip. in	32°F night	Nights ≤ 32°F	GDD 50°F
Jan	37	17	1.4	100%	28	1
Feb	43	21	1.9	100%	24	6
Mar	55	31	2.5	100%	17	54
Apr	66	41	3.9	91%	5	176
May	75	53	5.1	11%	<1	441
Jun	84	63	5.4	0%	0	708
Jul	88	67	4.3	0%	0	852
Aug	87	65	4.4	0%	0	797
Sep	80	56	4.3	3%	0	531
Oct	68	43	3.2	84%	3	224
Nov	54	32	2.2	100%	15	43
Dec	42	23	1.6	100%	26	4

Monthly normals 1991–2020 at Carrollton, MO (705 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.

Compared with the next station

The nearest other station, Marshall, MO, 21 miles southeast of Carrollton, has a last frost 6 days earlier (April 10), a first frost 1 day later (October 24), a season 9 days longer.

Frost dates for 65340 (Marshall) →

When it snows in Carrollton, Missouri

The first measurable snow (0.1 inch or more) in Carrollton usually arrives around December 9, and the last of the season around March 1. Those are the middle dates across the winters of 1991–2020 at Carrollton, MO, 0.5 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 46 days after the last snow.

Planting calendar for 64633

What to do and when, from the 50% frost dates for Carrollton, Missouri
When	What to do
February 5 – February 19	Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 19 – March 5	Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 19 – April 2	Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 16 onward	Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 31	Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 9	Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 23 onward	Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter.

The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.

Where these figures come from

ZIP 64633 is under a mile from Carrollton, MO, which stands at 705 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 64633 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Missouri →

Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.

Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.