USDA Hardiness Zone 6b
Frost Dates for 45159 — New Vienna, Ohio
NOAA 1991–2020 normals from Hillsboro, OH (953 ft), 8 miles southeast.
Updated
In New Vienna, the last spring frost (32°F) is around April 24 in half of years and has passed by May 11 in nine years out of ten. The first fall frost comes around October 20, as early as October 6 one year in ten, leaving a typical freeze-free season of 178 days (NOAA, Hillsboro, OH).
- Last spring frost
- April 24
- First fall frost
- October 20
- Growing season
- 178 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- December 16
- Last snow
- March 15
- Winters with snow
- 100%
- Snow per year
- 18.1"
median, 1991–2020
median, 1991–2020
24 of 24 observed
NOAA normal
Frost risk by date in New Vienna
Half of springs at Hillsboro, OH see their last 32°F night by April 24; only one in ten is past it by April 10, and one in ten still has one after May 11. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 5 20%, and after May 11 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 24% 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 6 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 12 days later, around November 1; in spring the one-in-ten date for 28°F is April 29, 12 days before the 32°F one. The freeze-free season lasts 178 days in a typical year, shorter than at 54% of the 148 Ohio stations; it reaches 196 days one year in ten and falls short of 157 one year in ten. On average 115 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 10 days longer, to about May 4, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 1 and March 14.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 21 | Apr 26 | Apr 28 | Apr 30 | May 4 | May 7 | May 10 | May 14 | May 20 |
| 32°F | Apr 10 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 5 | May 11 |
| 28°F | Mar 31 | Apr 3 | Apr 6 | Apr 9 | Apr 12 | Apr 16 | Apr 18 | Apr 22 | Apr 29 |
| 24°F | Mar 18 | Mar 23 | Mar 29 | Mar 31 | Apr 2 | Apr 5 | Apr 8 | Apr 12 | Apr 17 |
| 20°F | Mar 5 | Mar 12 | Mar 17 | Mar 20 | Mar 24 | Mar 28 | Mar 31 | Apr 2 | Apr 6 |
| 16°F | Feb 22 | Mar 1 | Mar 5 | Mar 9 | Mar 14 | Mar 17 | Mar 20 | Mar 24 | Mar 31 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 27 | Oct 1 | Oct 4 | Oct 6 | Oct 10 | Oct 12 | Oct 14 | Oct 16 | Oct 20 |
| 32°F | Oct 6 | Oct 12 | Oct 15 | Oct 18 | Oct 20 | Oct 22 | Oct 25 | Oct 27 | Nov 1 |
| 28°F | Oct 17 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 2 | Nov 5 | Nov 8 | Nov 13 |
| 24°F | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 21 | Nov 28 |
| 20°F | Nov 6 | Nov 10 | Nov 13 | Nov 17 | Nov 20 | Nov 25 | Nov 29 | Dec 3 | Dec 10 |
| 16°F | Nov 13 | Nov 18 | Nov 23 | Nov 27 | Dec 1 | Dec 5 | Dec 10 | Dec 17 | Dec 25 |
Freeze probabilities 1991–2020 at Hillsboro, 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 45159 →Compare New Vienna with another place →
Weather by month in New Vienna
July is the warmest month at Hillsboro, OH, averaging 85°F by day and 62°F at night; January is the coldest at 39°F and 19°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 30% of years.
Warmth for growing adds up to 3,283 growing degree days a year (base 50°F), more than at 58% of the 148 Ohio stations. 36% of them (1,181) have built up by the end of June, and July adds the most, 719. Precipitation totals 46.8 inches a year, most in May (5.1") and least in November (3.1"); May to September bring 45% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 39 | 19 | 3.4 | 100% | 26 | 5 |
| Feb | 43 | 22 | 3.3 | 100% | 23 | 8 |
| Mar | 53 | 29 | 4.2 | 100% | 18 | 46 |
| Apr | 65 | 39 | 4.9 | 98% | 6 | 150 |
| May | 74 | 50 | 5.1 | 30% | <1 | 373 |
| Jun | 82 | 59 | 4.8 | 0% | 0 | 600 |
| Jul | 85 | 62 | 4.3 | 0% | 0 | 719 |
| Aug | 83 | 60 | 3.7 | 0% | 0 | 676 |
| Sep | 78 | 53 | 3.2 | 3% | 0 | 466 |
| Oct | 67 | 42 | 3.2 | 89% | 3 | 189 |
| Nov | 54 | 32 | 3.1 | 100% | 16 | 43 |
| Dec | 43 | 25 | 3.6 | 100% | 23 | 9 |
Monthly normals 1991–2020 at Hillsboro, OH (953 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, Cincinnati, OH, 10 miles northwest of New Vienna, has a last frost 5 days earlier (April 19), a first frost 2 days later (October 22), a season 7 days longer.
When it snows in New Vienna, Ohio
The first measurable snow (0.1 inch or more) in New Vienna usually arrives around December 16, and the last of the season around March 15. Those are the middle dates across the winters of 1991–2020 at Hillsboro, OH, 7.7 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 40 days after the last snow.
Planting calendar for 45159
| When | What to do |
|---|---|
| February 13 – February 27 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 27 – March 13 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 27 – April 10 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 24 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 28 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 6 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 20 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 45159 is 8 miles from Hillsboro, OH, which stands at 953 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 45133 (Hillsboro). The 2023 USDA Plant Hardiness Zone Map lists ZIP 45159 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.
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.