USDA Hardiness Zone 6a
Frost Dates for 46637 — South Bend, Indiana
NOAA 1991–2020 normals from S Bend, IN (710 ft), 2 miles south.
Updated
In South Bend, 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 23, as early as October 9 one year in ten, leaving a typical freeze-free season of 181 days (NOAA, S Bend, IN).
- Last spring frost
- April 23
- First fall frost
- October 23
- 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
- November 17
- Last snow
- April 6
- Winters with snow
- 100%
- Snow per year
- 64.5"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in South Bend
Half of springs at S Bend, IN see their last 32°F night by April 23; only one in ten is past it by April 11, 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 3 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 23 in half of years, as early as October 9 one year in ten, and holds off past November 5 one year in ten. A hard freeze of 28°F follows 11 days later, around November 3; 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 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 162 one year in ten. On average 133 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 12. Severe cold of 16°F or below comes every winter, usually between December 6 and March 12.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 20 | Apr 24 | Apr 28 | Apr 30 | May 3 | May 6 | May 9 | May 13 | May 18 |
| 32°F | Apr 11 | Apr 15 | Apr 18 | Apr 21 | Apr 23 | Apr 26 | Apr 30 | May 3 | May 9 |
| 28°F | Mar 30 | Apr 3 | Apr 5 | Apr 9 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 28 |
| 24°F | Mar 17 | Mar 23 | Mar 27 | Mar 30 | Apr 1 | Apr 3 | Apr 6 | Apr 11 | Apr 16 |
| 20°F | Mar 4 | Mar 11 | Mar 16 | Mar 19 | Mar 23 | Mar 26 | Mar 29 | Mar 31 | Apr 5 |
| 16°F | Feb 22 | Feb 28 | Mar 5 | Mar 9 | Mar 12 | Mar 16 | Mar 19 | Mar 24 | Mar 29 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 28 | Oct 2 | Oct 6 | Oct 9 | Oct 12 | Oct 14 | Oct 17 | Oct 20 | Oct 24 |
| 32°F | Oct 9 | Oct 14 | Oct 18 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 5 |
| 28°F | Oct 21 | Oct 25 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 13 | Nov 21 |
| 24°F | Nov 2 | Nov 5 | Nov 9 | Nov 13 | Nov 16 | Nov 20 | Nov 23 | Nov 27 | Dec 2 |
| 20°F | Nov 9 | Nov 14 | Nov 19 | Nov 23 | Nov 26 | Nov 30 | Dec 3 | Dec 7 | Dec 15 |
| 16°F | Nov 19 | Nov 26 | Nov 30 | Dec 3 | Dec 6 | Dec 10 | Dec 14 | Dec 20 | Dec 24 |
Freeze probabilities 1991–2020 at S Bend, 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 46637 →Compare South Bend with another place →
Compared with the next station
The nearest other station, South Bend Michiana Regional Airport, IN, 4 miles southwest of South Bend, has a last frost 8 days later (May 1), a first frost 4 days earlier (October 19), a season 11 days shorter.
When it snows in South Bend, Indiana
The first measurable snow (0.1 inch or more) in South Bend usually arrives around November 17, and the last of the season around April 6. Those are the middle dates across the winters of 1991–2020 at South Bend Michiana Regional Airport, IN, 4.1 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 17 days after the last snow.
Planting calendar for 46637
| 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 31 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 9 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 23 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 46637 is 2 miles from S Bend, IN, which stands at 710 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 12 other ZIP codes share the station; its figures are presented in full for 46530 (Granger). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46637 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.