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USDA Hardiness Zone 6a

Frost Dates for 45390 — Union City, Ohio

NOAA 1991–2020 normals from Winchester Airport 3 E, IN (1,110 ft), 8 miles west.

Updated

In Union City, the last spring frost (32°F) is around April 20 in half of years and has passed by May 5 in nine years out of ten. The first fall frost comes around October 21, as early as October 7 one year in ten, leaving a typical freeze-free season of 183 days (NOAA, Winchester Airport 3 E, IN).

Last spring frost
April 20

50% probability

First fall frost
October 21

50% probability

Growing season
183 days

freeze-free, 50%

Hardiness zone
6a

-10 to -5°F (-23.3 to -20.6°C) coldest night

First snow
December 13

median, 1991–2020

Last snow
March 19

median, 1991–2020

Winters with snow
100%

20 of 20 observed

Snow per year
—

NOAA normal

Frost risk by date in Union City

Half of springs at Winchester Airport 3 E, IN see their last 32°F night by April 20; only one in ten is past it by April 6, and one in ten still has one after May 5. Planting tender crops after April 27 leaves a 30% risk of a frost on them, after April 30 20%, and after May 5 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 77% of the 148 Ohio stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 21 in half of years, as early as October 7 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 11 days later, around November 1; in spring the one-in-ten date for 28°F is April 25, 10 days before the 32°F one. The freeze-free season lasts 183 days in a typical year, longer than at 59% of the 148 Ohio stations; it reaches 202 days one year in ten and falls short of 161 one year in ten. On average 124 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 May 1, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 5 and March 11.

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

Freeze probabilities 1991–2020 at Winchester Airport 3 E, IN, 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 45390 →Compare Union City with another place →

Weather by month in Union City

July is the warmest month at Winchester Airport 3 E, IN, averaging 83°F by day and 64°F at night; January is the coldest at 33°F and 18°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 3,183 growing degree days a year (base 50°F), fewer than at 57% of the 148 Ohio stations. 36% of them (1,134) have built up by the end of June, and July adds the most, 719. Precipitation totals 39.9 inches a year, most in June (4.8") and least in February (2.1"); May to September bring 49% of it.

Monthly normals 1991–2020 at Winchester Airport 3 E, IN
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan33182.7100%272
Feb37202.1100%252
Mar48292.9100%2029
Apr61404.097%6131
May71524.419%<1367
Jun79614.80%0603
Jul83643.90%0719
Aug81613.50%0657
Sep76543.03%<1455
Oct64433.186%4180
Nov50323.2100%1634
Dec38242.3100%264

Monthly normals 1991–2020 at Winchester Airport 3 E, IN (1,110 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, Greenville Wtp, OH, 10 miles southeast of Union City, has a last frost 1 day later (April 21), a first frost 1 day earlier (October 20), a season 3 days shorter.

Frost dates for 45331 (Greenville) →

When it snows in Union City, Ohio

The first measurable snow (0.1 inch or more) in Union City usually arrives around December 13, and the last of the season around March 19. Those are the middle dates across the winters of 1991–2020 at Winchester Airport 3 E, IN, 7.6 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 45390

What to do and when, from the 50% frost dates for Union City, Ohio
WhenWhat to do
February 9 – February 23Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 23 – March 9Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 23 – April 6Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 20 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 29Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 7Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 21 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 45390 is 8 miles from Winchester Airport 3 E, IN, which stands at 1,110 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 47394 (Winchester). The 2023 USDA Plant Hardiness Zone Map lists ZIP 45390 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 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 6a places in Ohio