USDA Hardiness Zone 6a
Frost Dates for 46172 — Roachdale, Indiana
NOAA 1991–2020 normals from Crawfordsville 6 SE, IN (836 ft), 11 miles north.
Updated
In Roachdale, the last spring frost (32°F) is around April 27 in half of years and has passed by May 13 in nine years out of ten. The first fall frost comes around October 12, as early as September 26 one year in ten, leaving a typical freeze-free season of 167 days (NOAA, Crawfordsville 6 SE, IN).
- Last spring frost
- April 27
- First fall frost
- October 12
- Growing season
- 167 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
- November 30
- Last snow
- March 6
- Winters with snow
- 100%
- Snow per year
- 21.7"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in Roachdale
Half of springs at Crawfordsville 6 SE, IN see their last 32°F night by April 27; only one in ten is past it by April 11, and one in ten still has one after May 13. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 13 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 12 in half of years, as early as September 26 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 11 days later, around October 23; in spring the one-in-ten date for 28°F is May 2, 11 days before the 32°F one. The freeze-free season lasts 167 days in a typical year, shorter than at 94% of the 125 Indiana stations; it reaches 188 days one year in ten and falls short of 146 one year in ten. On average 140 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 7, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 30 and March 13.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 22 | Apr 27 | May 1 | May 4 | May 7 | May 10 | May 13 | May 18 | May 22 |
| 32°F | Apr 11 | Apr 16 | Apr 20 | Apr 23 | Apr 27 | Apr 30 | May 4 | May 7 | May 13 |
| 28°F | Mar 31 | Apr 4 | Apr 7 | Apr 11 | Apr 14 | Apr 18 | Apr 21 | Apr 25 | May 2 |
| 24°F | Mar 17 | Mar 23 | Mar 27 | Mar 31 | Apr 2 | Apr 5 | Apr 9 | Apr 15 | Apr 21 |
| 20°F | Mar 5 | Mar 12 | Mar 16 | Mar 20 | Mar 23 | Mar 27 | Mar 31 | Apr 3 | Apr 9 |
| 16°F | Feb 24 | Mar 2 | Mar 6 | Mar 10 | Mar 13 | Mar 16 | Mar 20 | Mar 27 | Mar 31 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 19 | Sep 24 | Sep 27 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 15 |
| 32°F | Sep 26 | Oct 2 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 20 | Oct 25 |
| 28°F | Oct 6 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 29 | Nov 1 | Nov 6 |
| 24°F | Oct 18 | Oct 24 | Oct 28 | Nov 1 | Nov 3 | Nov 5 | Nov 9 | Nov 15 | Nov 23 |
| 20°F | Nov 1 | Nov 4 | Nov 8 | Nov 12 | Nov 16 | Nov 20 | Nov 25 | Nov 30 | Dec 6 |
| 16°F | Nov 10 | Nov 15 | Nov 21 | Nov 25 | Nov 30 | Dec 2 | Dec 6 | Dec 10 | Dec 18 |
Freeze probabilities 1991–2020 at Crawfordsville 6 SE, 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 46172 →Compare Roachdale with another place →
Weather by month in Roachdale
July is the warmest month at Crawfordsville 6 SE, IN, averaging 83°F by day and 62°F at night; January is the coldest at 33°F and 17°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 39% of years.
Warmth for growing adds up to 3,079 growing degree days a year (base 50°F), fewer than at 77% of the 125 Indiana stations. 36% of them (1,108) have built up by the end of June, and July adds the most, 693. Precipitation totals 44.2 inches a year, most in June (5.3") and least in February (2.5"); May to September bring 48% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 33 | 17 | 2.9 | 100% | 28 | 3 |
| Feb | 38 | 20 | 2.5 | 100% | 25 | 3 |
| Mar | 49 | 29 | 3.2 | 100% | 22 | 35 |
| Apr | 61 | 39 | 4.4 | 99% | 10 | 122 |
| May | 72 | 50 | 4.5 | 39% | 1 | 348 |
| Jun | 80 | 60 | 5.3 | 0% | 0 | 599 |
| Jul | 83 | 62 | 4.4 | 0% | 0 | 693 |
| Aug | 82 | 59 | 3.9 | 0% | 0 | 637 |
| Sep | 77 | 52 | 3.2 | 17% | 1 | 436 |
| Oct | 65 | 41 | 3.4 | 95% | 8 | 167 |
| Nov | 50 | 31 | 3.6 | 100% | 18 | 34 |
| Dec | 38 | 23 | 2.9 | 100% | 26 | 5 |
Monthly normals 1991–2020 at Crawfordsville 6 SE, IN (836 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, Jamestown 2 E, IN, 14 miles northeast of Roachdale, has a last frost 4 days earlier (April 23), a first frost 7 days later (October 19), a season 11 days longer.
When it snows in Roachdale, Indiana
The first measurable snow (0.1 inch or more) in Roachdale usually arrives around November 30, and the last of the season around March 6. Those are the middle dates across the winters of 1991–2020 at Crawfordsville 6 SE, IN, 11.2 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 52 days after the last snow.
Planting calendar for 46172
| When | What to do |
|---|---|
| February 16 – March 2 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 2 – March 16 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 30 – April 13 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 27 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 20 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 28 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 12 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 46172 is 11 miles from Crawfordsville 6 SE, IN, which stands at 836 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 47933 (Crawfordsville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46172 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.