USDA Hardiness Zone 6a
Frost Dates for 46628 — South Bend, Indiana
NOAA 1991–2020 normals from South Bend Michiana Regional Airport, IN (773 ft), under a mile northwest.
Updated
In South Bend, the last spring frost (32°F) is around May 1 in half of years and has passed by May 17 in nine years out of ten. The first fall frost comes around October 19, as early as October 5 one year in ten, leaving a typical freeze-free season of 170 days (NOAA, South Bend Michiana Regional Airport, IN).
- Last spring frost
- May 1
- First fall frost
- October 19
- Growing season
- 170 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 South Bend Michiana Regional Airport, IN see their last 32°F night by May 1; only one in ten is past it by April 16, and one in ten still has one after May 17. Planting tender crops after May 7 leaves a 30% risk of a frost on them, after May 11 20%, and after May 17 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 5 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 12 days later, around October 31; in spring the one-in-ten date for 28°F is May 5, 12 days before the 32°F one. The freeze-free season lasts 170 days in a typical year, shorter than at 89% of the 125 Indiana stations; it reaches 189 days one year in ten and falls short of 149 one year in ten. On average 126 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 11, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 1 and March 18.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 27 | May 1 | May 5 | May 8 | May 11 | May 15 | May 18 | May 23 | May 27 |
| 32°F | Apr 16 | Apr 20 | Apr 24 | Apr 28 | May 1 | May 4 | May 7 | May 11 | May 17 |
| 28°F | Apr 4 | Apr 9 | Apr 13 | Apr 16 | Apr 19 | Apr 22 | Apr 25 | Apr 30 | May 5 |
| 24°F | Mar 26 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 11 | Apr 14 | Apr 17 | Apr 21 |
| 20°F | Mar 13 | Mar 19 | Mar 22 | Mar 26 | Mar 29 | Mar 31 | Apr 2 | Apr 5 | Apr 11 |
| 16°F | Feb 28 | Mar 7 | Mar 12 | Mar 15 | Mar 18 | Mar 21 | Mar 25 | Mar 28 | Apr 1 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 9 | Oct 12 | Oct 14 | Oct 19 |
| 32°F | Oct 5 | Oct 10 | Oct 14 | Oct 17 | Oct 19 | Oct 21 | Oct 24 | Oct 27 | Nov 1 |
| 28°F | Oct 19 | Oct 23 | Oct 26 | Oct 29 | Oct 31 | Nov 2 | Nov 4 | Nov 8 | Nov 13 |
| 24°F | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 14 | Nov 18 | Nov 22 | Nov 29 |
| 20°F | Nov 6 | Nov 11 | Nov 15 | Nov 18 | Nov 21 | Nov 25 | Nov 29 | Dec 2 | Dec 8 |
| 16°F | Nov 13 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 3 | Dec 7 | Dec 12 | Dec 19 |
Freeze probabilities 1991–2020 at South Bend Michiana Regional Airport, 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 46628 →Compare South Bend with another place →
Weather by month in South Bend
July is the warmest month at South Bend Michiana Regional Airport, IN, averaging 83°F by day and 62°F at night; January is the coldest at 31°F and 17°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 51% of years.
Warmth for growing adds up to 2,905 growing degree days a year (base 50°F), fewer than at 97% of the 125 Indiana stations. 34% of them (984) have built up by the end of June, and July adds the most, 694. Precipitation totals 39.3 inches a year, most in May (4.2") and least in February (2.3"); May to September bring 50% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 31 | 17 | 2.7 | 100% | 28 | 0 |
| Feb | 35 | 19 | 2.3 | 100% | 25 | 2 |
| Mar | 46 | 27 | 2.4 | 100% | 21 | 25 |
| Apr | 59 | 37 | 3.5 | 100% | 9 | 92 |
| May | 70 | 48 | 4.2 | 51% | 1 | 303 |
| Jun | 79 | 58 | 4.0 | 0% | 0 | 563 |
| Jul | 83 | 62 | 3.8 | 0% | 0 | 694 |
| Aug | 81 | 61 | 4.0 | 0% | 0 | 640 |
| Sep | 74 | 53 | 3.5 | 4% | 0 | 414 |
| Oct | 62 | 42 | 3.7 | 88% | 3 | 145 |
| Nov | 48 | 32 | 2.8 | 100% | 15 | 25 |
| Dec | 36 | 23 | 2.4 | 100% | 25 | 3 |
Monthly normals 1991–2020 at South Bend Michiana Regional Airport, IN (773 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, S Bend, IN, 3 miles east of South Bend, has a last frost 8 days earlier (April 23), a first frost 4 days later (October 23), a season 11 days longer.
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, 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 25 days after the last snow.
Planting calendar for 46628
| When | What to do |
|---|---|
| February 20 – March 6 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 6 – March 20 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 3 – April 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 1 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 46628 is under a mile from South Bend Michiana Regional Airport, IN, which stands at 773 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 46628 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.