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USDA Hardiness Zone 6a

Frost Dates for 45365 — Sidney, Ohio

NOAA 1991–2020 normals from Sidney 1 S, OH (940 ft), 1 miles southeast.

Updated

In Sidney, the last spring frost (32°F) is around April 27 in half of years and has passed by May 12 in nine years out of ten. The first fall frost comes around October 20, as early as October 5 one year in ten, leaving a typical freeze-free season of 175 days (NOAA, Sidney 1 S, OH).

Last spring frost
April 27

50% probability

First fall frost
October 20

50% probability

Growing season
175 days

freeze-free, 50%

Hardiness zone
6a

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

First snow
December 6

median, 1991–2020

Last snow
March 17

median, 1991–2020

Winters with snow
100%

22 of 22 observed

Snow per year
15.2"

NOAA normal

Frost risk by date in Sidney

Half of springs at Sidney 1 S, OH see their last 32°F night by April 27; only one in ten is past it by April 12, and one in ten still has one after May 12. Planting tender crops after May 3 leaves a 30% risk of a frost on them, after May 6 20%, and after May 12 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 20 in half of years, as early as October 5 one year in ten, and holds off past November 2 one year in ten. A hard freeze of 28°F follows 11 days later, around October 31; in spring the one-in-ten date for 28°F is May 2, 10 days before the 32°F one. The freeze-free season lasts 175 days in a typical year, shorter than at 68% of the 148 Ohio stations; it reaches 194 days one year in ten and falls short of 156 one year in ten. On average 134 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 8 days longer, to about May 5, and return around October 8. Severe cold of 16°F or below comes every winter, usually between December 4 and March 13.

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

Freeze probabilities 1991–2020 at Sidney 1 S, 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 45365 →Compare Sidney with another place →

Weather by month in Sidney

July is the warmest month at Sidney 1 S, OH, averaging 84°F by day and 62°F at night; January is the coldest at 34°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 38% of years.

Warmth for growing adds up to 3,156 growing degree days a year (base 50°F), fewer than at 60% of the 148 Ohio stations. 35% of them (1,108) have built up by the end of June, and July adds the most, 719. Precipitation totals 41.8 inches a year, most in June (4.7") and least in February (2.3"); May to September bring 49% of it.

Monthly normals 1991–2020 at Sidney 1 S, OH
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan34182.9100%273
Feb39202.3100%254
Mar49283.2100%2230
Apr62384.199%9119
May73494.138%1352
Jun81594.70%0602
Jul84624.60%0719
Aug83603.80%0663
Sep78533.14%<1458
Oct65422.985%6171
Nov51323.2100%1831
Dec40242.9100%265

Monthly normals 1991–2020 at Sidney 1 S, OH (940 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, Piqua Wwtp, OH, 11 miles south of Sidney, has a last frost 9 days earlier (April 18), a first frost 3 days later (October 23), a season 11 days longer.

Frost dates for 45373 (Troy) →

When it snows in Sidney, Ohio

The first measurable snow (0.1 inch or more) in Sidney usually arrives around December 6, and the last of the season around March 17. Those are the middle dates across the winters of 1991–2020 at Piqua, OH, 10 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 41 days after the last snow.

Planting calendar for 45365

What to do and when, from the 50% frost dates for Sidney, Ohio
WhenWhat to do
February 16 – March 2Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 2 – March 16Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 30 – April 13Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 27 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 28Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 6Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 20 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 45365 is 1 mile from Sidney 1 S, OH, which stands at 940 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 45365 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