USDA Hardiness Zone 6a
Frost Dates for 47841 — Clay City, Indiana
NOAA 1991–2020 normals from Shakamak Sp, IN (549 ft), 11 miles southwest.
Updated
In Clay City, the last spring frost (32°F) is around April 14 in half of years and has passed by May 1 in nine years out of ten. The first fall frost comes around October 26, as early as October 12 one year in ten, leaving a typical freeze-free season of 193 days (NOAA, Shakamak Sp, IN).
- Last spring frost
- April 14
- First fall frost
- October 26
- Growing season
- 193 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 7
- Last snow
- March 10
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Clay City
Half of springs at Shakamak Sp, IN see their last 32°F night by April 14; only one in ten is past it by March 31, and one in ten still has one after May 1. Planting tender crops after April 20 leaves a 30% risk of a frost on them, after April 24 20%, and after May 1 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 66% of the 125 Indiana 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 12 one year in ten, and holds off past November 6 one year in ten. A hard freeze of 28°F follows 8 days later, around November 3; in spring the one-in-ten date for 28°F is April 17, 14 days before the 32°F one. The freeze-free season lasts 193 days in a typical year, longer than at 75% of the 125 Indiana stations; it reaches 212 days one year in ten and falls short of 172 one year in ten. On average 113 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 April 25, and return around October 16. Severe cold of 16°F or below comes every winter, usually between December 6 and March 3.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 10 | Apr 15 | Apr 18 | Apr 22 | Apr 25 | Apr 28 | May 2 | May 6 | May 11 |
| 32°F | Mar 31 | Apr 4 | Apr 8 | Apr 10 | Apr 14 | Apr 16 | Apr 20 | Apr 24 | May 1 |
| 28°F | Mar 19 | Mar 24 | Mar 28 | Mar 31 | Apr 1 | Apr 4 | Apr 7 | Apr 11 | Apr 17 |
| 24°F | Mar 5 | Mar 12 | Mar 16 | Mar 20 | Mar 24 | Mar 27 | Mar 29 | Apr 1 | Apr 7 |
| 20°F | Feb 23 | Mar 1 | Mar 6 | Mar 10 | Mar 13 | Mar 16 | Mar 19 | Mar 24 | Mar 28 |
| 16°F | Feb 8 | Feb 16 | Feb 23 | Feb 28 | Mar 3 | Mar 6 | Mar 11 | Mar 15 | Mar 20 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 3 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 21 | Oct 24 | Oct 28 |
| 32°F | Oct 12 | Oct 17 | Oct 21 | Oct 23 | Oct 26 | Oct 28 | Oct 30 | Nov 2 | Nov 6 |
| 28°F | Oct 23 | Oct 27 | Oct 31 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 17 |
| 24°F | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 25 | Dec 1 |
| 20°F | Nov 7 | Nov 12 | Nov 16 | Nov 21 | Nov 25 | Nov 29 | Dec 3 | Dec 8 | Dec 15 |
| 16°F | Nov 14 | Nov 23 | Nov 28 | Dec 1 | Dec 6 | Dec 10 | Dec 15 | Dec 21 | Dec 27 |
Freeze probabilities 1991–2020 at Shakamak Sp, 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 47841 →Compare Clay City with another place →
Weather by month in Clay City
July is the warmest month at Shakamak Sp, IN, averaging 86°F by day and 66°F at night; January is the coldest at 38°F and 21°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 88% of years and May still brings one in 10% of years.
Warmth for growing adds up to 3,846 growing degree days a year (base 50°F), more than at 76% of the 125 Indiana stations. 37% of them (1,420) have built up by the end of June, and July adds the most, 804.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 38 | 21 | 100% | 26 | 5 |
| Feb | 43 | 24 | 100% | 23 | 8 |
| Mar | 53 | 33 | 100% | 17 | 61 |
| Apr | 66 | 44 | 88% | 4 | 209 |
| May | 75 | 54 | 10% | <1 | 452 |
| Jun | 83 | 63 | 0% | 0 | 685 |
| Jul | 86 | 66 | 0% | 0 | 804 |
| Aug | 85 | 65 | 0% | 0 | 767 |
| Sep | 79 | 57 | 0% | <1 | 548 |
| Oct | 68 | 45 | 74% | 3 | 244 |
| Nov | 54 | 34 | 100% | 15 | 55 |
| Dec | 43 | 26 | 100% | 23 | 8 |
Monthly normals 1991–2020 at Shakamak Sp, IN (549 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, Farmersburg Tv-2, IN, 15 miles west of Clay City, has a last frost 6 days earlier (April 8), a first frost 1 day later (October 27), a season 8 days longer.
When it snows in Clay City, Indiana
The first measurable snow (0.1 inch or more) in Clay City usually arrives around December 7, and the last of the season around March 10. Those are the middle dates across the winters of 1991–2020 at Shakamak Sp, IN, 10.8 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 35 days after the last snow.
Planting calendar for 47841
| When | What to do |
|---|---|
| February 3 – February 17 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 17 – March 3 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 17 – March 31 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 14 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 3 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 12 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 26 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 47841 is 11 miles from Shakamak Sp, IN, which stands at 549 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 47441 (Linton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 47841 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.