USDA Hardiness Zone 6a
Frost Dates for 47390 — Union City, Indiana
NOAA 1991–2020 normals from Winchester Airport 3 E, IN (1,110 ft), 5 miles southwest.
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
- First fall frost
- October 21
- Growing season
- 183 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- December 13
- Last snow
- March 19
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
20 of 20 observed
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 70% of the 125 Indiana 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 54% of the 125 Indiana 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.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 18 | Apr 22 | Apr 25 | Apr 28 | May 1 | May 4 | May 7 | May 10 | May 16 |
| 32°F | Apr 6 | Apr 11 | Apr 14 | Apr 18 | Apr 20 | Apr 23 | Apr 27 | Apr 30 | May 5 |
| 28°F | Mar 26 | Apr 1 | Apr 3 | Apr 6 | Apr 9 | Apr 12 | Apr 16 | Apr 19 | Apr 25 |
| 24°F | Mar 16 | Mar 20 | Mar 24 | Mar 27 | Mar 30 | Apr 1 | Apr 3 | Apr 6 | Apr 13 |
| 20°F | Mar 5 | Mar 11 | Mar 14 | Mar 17 | Mar 20 | Mar 23 | Mar 27 | Mar 30 | Apr 3 |
| 16°F | Feb 20 | Feb 28 | Mar 4 | Mar 8 | Mar 11 | Mar 14 | Mar 17 | Mar 20 | Mar 26 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 27 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 15 | Oct 18 | Oct 22 |
| 32°F | Oct 7 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 29 | Nov 1 |
| 28°F | Oct 19 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 5 | Nov 10 | Nov 15 |
| 24°F | Oct 30 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 19 | Nov 23 | Nov 30 |
| 20°F | Nov 7 | Nov 12 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 14 |
| 16°F | Nov 15 | Nov 21 | Nov 27 | Dec 1 | Dec 5 | Dec 9 | Dec 14 | Dec 20 | Dec 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 47390 →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 65% of the 125 Indiana 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.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 33 | 18 | 2.7 | 100% | 27 | 2 |
| Feb | 37 | 20 | 2.1 | 100% | 25 | 2 |
| Mar | 48 | 29 | 2.9 | 100% | 20 | 29 |
| Apr | 61 | 40 | 4.0 | 97% | 6 | 131 |
| May | 71 | 52 | 4.4 | 19% | <1 | 367 |
| Jun | 79 | 61 | 4.8 | 0% | 0 | 603 |
| Jul | 83 | 64 | 3.9 | 0% | 0 | 719 |
| Aug | 81 | 61 | 3.5 | 0% | 0 | 657 |
| Sep | 76 | 54 | 3.0 | 3% | <1 | 455 |
| Oct | 64 | 43 | 3.1 | 86% | 4 | 180 |
| Nov | 50 | 32 | 3.2 | 100% | 16 | 34 |
| Dec | 38 | 24 | 2.3 | 100% | 26 | 4 |
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, 12 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.
When it snows in Union City, Indiana
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, 5.4 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 47390
| When | What to do |
|---|---|
| February 9 – February 23 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 23 – March 9 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 23 – April 6 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 20 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 29 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 7 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 21 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 47390 is 5 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 47390 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.
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.