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USDA Hardiness Zone 6b

Frost Dates for 45224 — Cincinnati, Ohio

NOAA 1991–2020 normals from Cheviot, OH (891 ft), 6 miles southwest.

Updated

In Cincinnati, the last spring frost (32°F) is around April 17 in half of years and has passed by May 5 in nine years out of ten. The first fall frost comes around October 26, as early as October 11 one year in ten, leaving a typical freeze-free season of 191 days (NOAA, Cheviot, OH).

Last spring frost
April 17

50% probability

First fall frost
October 26

50% probability

Growing season
191 days

freeze-free, 50%

Hardiness zone
6b

-5 to 0°F (-20.6 to -17.8°C) coldest night

First snow
December 7

median, 1991–2020

Last snow
March 16

median, 1991–2020

Winters with snow
100%

20 of 20 observed

Snow per year
16"

NOAA normal

Frost risk by date in Cincinnati

Half of springs at Cheviot, OH see their last 32°F night by April 17; only one in ten is past it by April 2, and one in ten still has one after May 5. Planting tender crops after April 24 leaves a 30% risk of a frost on them, after April 30 20%, and after May 5 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 76% of the 148 Ohio stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 26 in half of years, as early as October 11 one year in ten, and holds off past November 7 one year in ten. A hard freeze of 28°F follows 9 days later, around November 4; in spring the one-in-ten date for 28°F is April 21, 14 days before the 32°F one. The freeze-free season lasts 191 days in a typical year, longer than at 84% of the 148 Ohio stations; it reaches 211 days one year in ten and falls short of 168 one year in ten. On average 106 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 12 days longer, to about April 29, and return around October 16. Severe cold of 16°F or below comes every winter, usually between December 11 and March 4.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FApr 14Apr 18Apr 21Apr 25Apr 29May 1May 5May 8May 13
32°FApr 2Apr 7Apr 11Apr 14Apr 17Apr 20Apr 24Apr 30May 5
28°FMar 20Mar 27Mar 31Apr 2Apr 4Apr 7Apr 11Apr 15Apr 21
24°FMar 8Mar 15Mar 18Mar 22Mar 25Mar 28Mar 31Apr 3Apr 8
20°FFeb 23Mar 3Mar 8Mar 12Mar 15Mar 17Mar 21Mar 24Mar 30
16°FFeb 9Feb 18Feb 25Mar 1Mar 4Mar 7Mar 12Mar 16Mar 21
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FOct 3Oct 7Oct 10Oct 13Oct 16Oct 18Oct 21Oct 24Oct 29
32°FOct 11Oct 17Oct 21Oct 23Oct 26Oct 28Oct 31Nov 3Nov 7
28°FOct 22Oct 28Oct 31Nov 2Nov 4Nov 7Nov 11Nov 15Nov 22
24°FNov 1Nov 4Nov 8Nov 12Nov 16Nov 20Nov 24Nov 29Dec 4
20°FNov 8Nov 16Nov 20Nov 25Nov 29Dec 2Dec 6Dec 11Dec 20
16°FNov 19Nov 27Dec 1Dec 7Dec 11Dec 17Dec 22Dec 26Dec 31

Freeze probabilities 1991–2020 at Cheviot, OH, 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 45224 →Compare Cincinnati with another place →

Weather by month in Cincinnati

July is the warmest month at Cheviot, OH, averaging 85°F by day and 65°F at night; January is the coldest at 37°F and 22°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 19% of years.

Warmth for growing adds up to 3,702 growing degree days a year (base 50°F), more than at 89% of the 148 Ohio stations. 37% of them (1,351) have built up by the end of June, and July adds the most, 787. Precipitation totals 48.3 inches a year, most in May (5.2") and least in February (3.2"); May to September bring 44% of it.

Monthly normals 1991–2020 at Cheviot, OH
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan37223.6100%266
Feb42253.2100%2211
Mar52334.5100%1657
Apr65434.992%4190
May74535.219%<1429
Jun82624.90%0658
Jul85654.30%0787
Aug85643.50%0753
Sep78573.31%0526
Oct66453.570%2222
Nov53353.4100%1351
Dec42274.0100%2311

Monthly normals 1991–2020 at Cheviot, OH (891 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, Cheviot 3 W, OH, 8 miles southwest of Cincinnati, has a last frost 1 day earlier (April 16), a first frost 2 days later (October 28), a season 2 days longer.

Frost dates for 45030 (Harrison) →

When it snows in Cincinnati, Ohio

The first measurable snow (0.1 inch or more) in Cincinnati usually arrives around December 7, and the last of the season around March 16. Those are the middle dates across the winters of 1991–2020 at Cheviot, OH, 5.8 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 32 days after the last snow.

Planting calendar for 45224

What to do and when, from the 50% frost dates for Cincinnati, Ohio
WhenWhat to do
February 6 – February 20Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 20 – March 6Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 20 – April 3Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 17 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 3Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 12Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 26 onwardPlant 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 45224 is 6 miles from Cheviot, OH, which stands at 891 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 14 other ZIP codes share the station; its figures are presented in full for 45238 (Cincinnati). The 2023 USDA Plant Hardiness Zone Map lists ZIP 45224 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Ohio →

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.

ZIP codes measured at the same station

Other zone 6b places in Ohio