USDA Hardiness Zone 6a
Frost Dates for 46167 — Pittsboro, Indiana
NOAA 1991–2020 normals from Jamestown 2 E, IN (962 ft), 8 miles northwest.
Updated
In Pittsboro, the last spring frost (32°F) is around April 23 in half of years and has passed by May 9 in nine years out of ten. The first fall frost comes around October 19, as early as October 4 one year in ten, leaving a typical freeze-free season of 178 days (NOAA, Jamestown 2 E, IN).
- Last spring frost
- April 23
- First fall frost
- October 19
- Growing season
- 178 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 6
- Winters with snow
- 100%
- Snow per year
- 14"
median, 1991–2020
median, 1991–2020
26 of 26 observed
NOAA normal
Frost risk by date in Pittsboro
Half of springs at Jamestown 2 E, IN see their last 32°F night by April 23; only one in ten is past it by April 8, and one in ten still has one after May 9. Planting tender crops after April 29 leaves a 30% risk of a frost on them, after May 2 20%, and after May 9 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 35% of the 125 Indiana stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 19 in half of years, as early as October 4 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 13 days later, around November 1; in spring the one-in-ten date for 28°F is April 28, 11 days before the 32°F one. The freeze-free season lasts 178 days in a typical year, shorter than at 62% of the 125 Indiana stations; it reaches 198 days one year in ten and falls short of 155 one year in ten. On average 127 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 3, and return around October 9. Severe cold of 16°F or below comes every winter, usually between December 1 and March 9.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 19 | Apr 24 | Apr 28 | Apr 30 | May 3 | May 6 | May 10 | May 15 | May 21 |
| 32°F | Apr 8 | Apr 13 | Apr 16 | Apr 19 | Apr 23 | Apr 25 | Apr 29 | May 2 | May 9 |
| 28°F | Mar 26 | Apr 1 | Apr 4 | Apr 6 | Apr 9 | Apr 13 | Apr 17 | Apr 21 | Apr 28 |
| 24°F | Mar 12 | Mar 18 | Mar 23 | Mar 28 | Mar 31 | Apr 1 | Apr 4 | Apr 8 | Apr 15 |
| 20°F | Mar 2 | Mar 8 | Mar 11 | Mar 15 | Mar 18 | Mar 21 | Mar 26 | Mar 31 | Apr 3 |
| 16°F | Feb 18 | Feb 26 | Mar 2 | Mar 6 | Mar 9 | Mar 12 | Mar 15 | Mar 18 | Mar 26 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 30 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 14 | Oct 18 | Oct 22 |
| 32°F | Oct 4 | Oct 11 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Nov 1 |
| 28°F | Oct 18 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 2 | Nov 5 | Nov 9 | Nov 14 |
| 24°F | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 | Nov 28 |
| 20°F | Nov 6 | Nov 10 | Nov 14 | Nov 18 | Nov 22 | Nov 25 | Nov 30 | Dec 4 | Dec 11 |
| 16°F | Nov 12 | Nov 19 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 10 | Dec 15 | Dec 21 |
Freeze probabilities 1991–2020 at Jamestown 2 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 46167 →Compare Pittsboro with another place →
Weather by month in Pittsboro
July is the warmest month at Jamestown 2 E, IN, averaging 83°F by day and 63°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 26% of years.
Warmth for growing adds up to 3,243 growing degree days a year (base 50°F), fewer than at 61% of the 125 Indiana stations. 36% of them (1,161) have built up by the end of June, and July adds the most, 711. Precipitation totals 43.3 inches a year, most in June (5.2") and least in February (2.4"); May to September bring 49% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 34 | 18 | 2.6 | 100% | 27 | 2 |
| Feb | 38 | 21 | 2.4 | 100% | 24 | 3 |
| Mar | 49 | 30 | 3.1 | 100% | 20 | 40 |
| Apr | 62 | 40 | 4.5 | 97% | 7 | 133 |
| May | 72 | 51 | 4.9 | 26% | <1 | 374 |
| Jun | 80 | 60 | 5.2 | 0% | 0 | 609 |
| Jul | 83 | 63 | 4.5 | 0% | 0 | 711 |
| Aug | 82 | 61 | 3.3 | 0% | 0 | 670 |
| Sep | 77 | 54 | 3.3 | 6% | <1 | 470 |
| Oct | 65 | 43 | 3.5 | 88% | 5 | 190 |
| Nov | 51 | 32 | 3.3 | 100% | 17 | 36 |
| Dec | 39 | 23 | 2.7 | 100% | 25 | 4 |
Monthly normals 1991–2020 at Jamestown 2 E, IN (962 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, Indianapolis Eagle Creek Airport, IN, 9 miles east of Pittsboro, has a last frost 11 days earlier (April 12), a first frost 10 days later (October 29), a season 20 days longer.
When it snows in Pittsboro, Indiana
The first measurable snow (0.1 inch or more) in Pittsboro usually arrives around December 7, and the last of the season around March 6. Those are the middle dates across the winters of 1991–2020 at Jamestown 2 E, IN, 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 48 days after the last snow.
Planting calendar for 46167
| When | What to do |
|---|---|
| February 12 – February 26 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 26 – March 12 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 26 – April 9 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 23 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 27 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 5 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 19 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 46167 is 8 miles from Jamestown 2 E, IN, which stands at 962 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 46122 (Danville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46167 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.