USDA Hardiness Zone 6b
Frost Dates for 47060 — West Harrison, Indiana
NOAA 1991–2020 normals from Brookville, IN (630 ft), 12 miles northwest.
Updated
In West Harrison, the last spring frost (32°F) is around April 20 in half of years and has passed by May 7 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 182 days (NOAA, Brookville, IN).
- Last spring frost
- April 20
- First fall frost
- October 21
- Growing season
- 182 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- December 10
- Last snow
- March 10
- Winters with snow
- 100%
- Snow per year
- 17.6"
median, 1991–2020
median, 1991–2020
22 of 22 observed
NOAA normal
Frost risk by date in West Harrison
Half of springs at Brookville, 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 7. Planting tender crops after April 26 leaves a 30% risk of a frost on them, after May 1 20%, and after May 7 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 21 in half of years, as early as October 6 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 10 days later, around October 31; in spring the one-in-ten date for 28°F is April 22, 15 days before the 32°F one. The freeze-free season lasts 182 days in a typical year, longer than at 51% of the 125 Indiana stations; it reaches 202 days one year in ten and falls short of 161 one year in ten. On average 119 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 April 30, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 6 and March 4.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 16 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 2 | May 6 | May 11 | May 17 |
| 32°F | Apr 6 | Apr 10 | Apr 14 | Apr 17 | Apr 20 | Apr 23 | Apr 26 | May 1 | May 7 |
| 28°F | Mar 23 | Mar 30 | Apr 2 | Apr 4 | Apr 6 | Apr 9 | Apr 13 | Apr 17 | Apr 22 |
| 24°F | Mar 11 | Mar 17 | Mar 21 | Mar 24 | Mar 27 | Mar 30 | Apr 1 | Apr 4 | Apr 8 |
| 20°F | Feb 26 | Mar 3 | Mar 8 | Mar 12 | Mar 15 | Mar 18 | Mar 21 | Mar 25 | Mar 31 |
| 16°F | Feb 11 | Feb 20 | Feb 25 | Mar 1 | Mar 4 | Mar 8 | Mar 11 | Mar 15 | Mar 21 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 10 | Oct 12 | Oct 15 | Oct 19 | Oct 23 |
| 32°F | Oct 6 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 30 | Nov 3 |
| 28°F | Oct 17 | Oct 22 | Oct 26 | Oct 29 | Oct 31 | Nov 2 | Nov 5 | Nov 9 | Nov 15 |
| 24°F | Oct 29 | Nov 1 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 24 | Dec 1 |
| 20°F | Nov 7 | Nov 13 | Nov 18 | Nov 22 | Nov 26 | Dec 1 | Dec 3 | Dec 8 | Dec 17 |
| 16°F | Nov 18 | Nov 25 | Nov 30 | Dec 2 | Dec 6 | Dec 11 | Dec 17 | Dec 22 | Dec 27 |
Freeze probabilities 1991–2020 at Brookville, 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 47060 →Compare West Harrison with another place →
Weather by month in West Harrison
July is the warmest month at Brookville, IN, averaging 87°F by day and 64°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 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 20% of years.
Warmth for growing adds up to 3,639 growing degree days a year (base 50°F), more than at 67% of the 125 Indiana stations. 36% of them (1,306) have built up by the end of June, and July adds the most, 787. Precipitation totals 44.0 inches a year, most in June (4.9") and least in February (2.7"); May to September bring 45% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 38 | 21 | 3.4 | 100% | 26 | 4 |
| Feb | 42 | 23 | 2.7 | 100% | 24 | 7 |
| Mar | 53 | 31 | 3.6 | 100% | 19 | 47 |
| Apr | 66 | 41 | 4.6 | 97% | 6 | 171 |
| May | 76 | 51 | 4.8 | 20% | 1 | 422 |
| Jun | 84 | 60 | 4.9 | 0% | 0 | 656 |
| Jul | 87 | 64 | 3.9 | 0% | 0 | 787 |
| Aug | 86 | 62 | 3.0 | 0% | 0 | 755 |
| Sep | 81 | 55 | 3.0 | 2% | <1 | 526 |
| Oct | 68 | 42 | 3.3 | 84% | 5 | 212 |
| Nov | 54 | 33 | 3.4 | 100% | 16 | 44 |
| Dec | 43 | 26 | 3.4 | 100% | 24 | 9 |
Monthly normals 1991–2020 at Brookville, IN (630 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, Milan 5 NE, IN, 13 miles southwest of West Harrison and 345 feet higher, has a last frost 10 days later (April 30), a first frost 5 days earlier (October 16), a season 14 days shorter.
When it snows in West Harrison, Indiana
The first measurable snow (0.1 inch or more) in West Harrison usually arrives around December 10, and the last of the season around March 10. Those are the middle dates across the winters of 1991–2020 at Brookville, IN, 11.9 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 41 days after the last snow.
Planting calendar for 47060
| 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 47060 is 12 miles from Brookville, IN, which stands at 630 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 47012 (Brookville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 47060 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°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.