USDA Hardiness Zone 6a
Frost Dates for 46970 — Peru, Indiana
NOAA 1991–2020 normals from Wabash, IN (665 ft), 13 miles east.
Updated
In Peru, 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 21, as early as October 6 one year in ten, leaving a typical freeze-free season of 181 days (NOAA, Wabash, IN).
- Last spring frost
- April 23
- First fall frost
- October 21
- Growing season
- 181 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 8
- Winters with snow
- 100%
- Snow per year
- 20.9"
median, 1991–2020
median, 1991–2020
25 of 25 observed
NOAA normal
Frost risk by date in Peru
Half of springs at Wabash, 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 30 leaves a 30% risk of a frost on them, after May 4 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 21 in half of years, as early as October 6 one year in ten, and holds off past November 4 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 29, 10 days before the 32°F one. The freeze-free season lasts 181 days in a typical year, shorter than at 50% of the 125 Indiana stations; it reaches 201 days one year in ten and falls short of 159 one year in ten. On average 131 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 4, and return around October 11. Severe cold of 16°F or below comes every winter, usually between December 4 and March 11.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 20 | Apr 25 | Apr 29 | May 1 | May 4 | May 7 | May 11 | May 15 | May 20 |
| 32°F | Apr 8 | Apr 13 | Apr 17 | Apr 20 | Apr 23 | Apr 27 | Apr 30 | May 4 | May 9 |
| 28°F | Mar 27 | Apr 1 | Apr 5 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 22 | Apr 29 |
| 24°F | Mar 15 | Mar 21 | Mar 25 | Mar 29 | Mar 31 | Apr 3 | Apr 6 | Apr 10 | Apr 16 |
| 20°F | Mar 4 | Mar 10 | Mar 14 | Mar 18 | Mar 21 | Mar 25 | Mar 29 | Apr 1 | Apr 6 |
| 16°F | Feb 21 | Feb 28 | Mar 4 | Mar 7 | Mar 11 | Mar 14 | Mar 17 | Mar 22 | Mar 29 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 27 | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 24 |
| 32°F | Oct 6 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 28 | Oct 31 | Nov 4 |
| 28°F | Oct 19 | Oct 24 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 16 |
| 24°F | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Dec 1 |
| 20°F | Nov 9 | Nov 13 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 15 |
| 16°F | Nov 16 | Nov 22 | Nov 26 | Dec 1 | Dec 4 | Dec 8 | Dec 13 | Dec 18 | Dec 24 |
Freeze probabilities 1991–2020 at Wabash, 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 46970 →Compare Peru with another place →
Frost risk through the year in Peru
In Peru, the spring curve drops under 10% on May 9 and the fall curve passes 10% on October 6, 150 days later; that gap is shorter than at 58% of the 125 Indiana stations with frost dates. The spring risk falls from 90% to 10% over 31 days (April 8 to May 9) and the fall risk climbs from 10% to 90% over 29 days (October 6 to November 4): both ends of the season vary about as much. At Logansport Cicott St, IN, 17 miles west, the same gap runs from May 6 to October 11, 8 days longer.
| Planted on | Another 32°F night | 28°F night |
|---|---|---|
| Apr 9 | 88% | 58% |
| Apr 16 | 73% | 37% |
| Apr 2350% date | 50% | 19% |
| Apr 30 | 30% | under 10% |
| May 7 | 14% | under 10% |
| May 14 | under 10% | under 10% |
Weather by month in Peru
July is the warmest month at Wabash, IN, averaging 85°F by day and 64°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 27% of years.
Warmth for growing adds up to 3,337 growing degree days a year (base 50°F), fewer than at 51% of the 125 Indiana stations. 35% of them (1,175) have built up by the end of June, and July adds the most, 750. Precipitation totals 40.4 inches a year, most in June (4.9") and least in February (2.3"); May to September bring 53% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 34 | 18 | 2.4 | 100% | 27 | 2 |
| Feb | 38 | 20 | 2.3 | 100% | 24 | 3 |
| Mar | 49 | 29 | 2.6 | 100% | 21 | 28 |
| Apr | 62 | 40 | 3.5 | 97% | 9 | 130 |
| May | 73 | 51 | 4.4 | 27% | 1 | 381 |
| Jun | 82 | 61 | 4.9 | 0% | 0 | 631 |
| Jul | 85 | 64 | 4.6 | 0% | 0 | 750 |
| Aug | 83 | 62 | 4.2 | 0% | 0 | 693 |
| Sep | 78 | 54 | 3.2 | 5% | <1 | 482 |
| Oct | 66 | 43 | 3.1 | 79% | 5 | 194 |
| Nov | 51 | 33 | 2.9 | 100% | 17 | 38 |
| Dec | 38 | 24 | 2.3 | 100% | 26 | 5 |
Monthly normals 1991–2020 at Wabash, IN (665 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, Logansport Cicott St, IN, 17 miles west of Peru, has a last frost 3 days earlier (April 20), a first frost 2 days later (October 23), a season 4 days longer.
When it snows in Peru, Indiana
The first measurable snow (0.1 inch or more) in Peru usually arrives around December 7, and the last of the season around March 8. Those are the middle dates across the winters of 1991–2020 at Peru, IN, 0.8 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 46 days after the last snow.
Planting calendar for 46970
| 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 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 46970 is 13 miles from Wabash, IN, which stands at 665 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 46970 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.