USDA Hardiness Zone 6a
Frost Dates for 46360 — Michigan City, Indiana
NOAA 1991–2020 normals from Laporte, IN (809 ft), 10 miles southeast.
Updated
In Michigan City, the last spring frost (32°F) is around April 19 in half of years and has passed by May 3 in nine years out of ten. The first fall frost comes around October 27, as early as October 14 one year in ten, leaving a typical freeze-free season of 191 days (NOAA, Laporte, IN).
- Last spring frost
- April 19
- First fall frost
- October 27
- Growing season
- 191 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 4
- Winters with snow
- 100%
- Snow per year
- 65.2"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in Michigan City
Half of springs at Laporte, IN see their last 32°F night by April 19; only one in ten is past it by April 5, and one in ten still has one after May 3. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 29 20%, and after May 3 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 89% of the 125 Indiana stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 27 in half of years, as early as October 14 one year in ten, and holds off past November 9 one year in ten. A hard freeze of 28°F follows 11 days later, around November 7; in spring the one-in-ten date for 28°F is April 22, 11 days before the 32°F one. The freeze-free season lasts 191 days in a typical year, longer than at 72% of the 125 Indiana stations; it reaches 209 days one year in ten and falls short of 171 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 11 days longer, to about April 30, and return around October 16. Severe cold of 16°F or below comes every winter, usually between December 5 and March 9.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 17 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 3 | May 5 | May 9 | May 14 |
| 32°F | Apr 5 | Apr 10 | Apr 13 | Apr 17 | Apr 19 | Apr 22 | Apr 25 | Apr 29 | May 3 |
| 28°F | Mar 25 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 17 | Apr 22 |
| 24°F | Mar 12 | Mar 18 | Mar 22 | Mar 25 | Mar 29 | Mar 31 | Apr 3 | Apr 6 | Apr 12 |
| 20°F | Mar 2 | Mar 7 | Mar 11 | Mar 15 | Mar 18 | Mar 21 | Mar 24 | Mar 28 | Apr 1 |
| 16°F | Feb 20 | Feb 27 | Mar 2 | Mar 5 | Mar 9 | Mar 12 | Mar 15 | Mar 18 | Mar 24 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 4 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 18 | Oct 21 | Oct 24 | Oct 29 |
| 32°F | Oct 14 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 28°F | Oct 26 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 9 | Nov 13 | Nov 17 | Nov 23 |
| 24°F | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 21 | Nov 25 | Nov 29 | Dec 3 |
| 20°F | Nov 10 | Nov 15 | Nov 20 | Nov 23 | Nov 27 | Dec 1 | Dec 3 | Dec 8 | Dec 14 |
| 16°F | Nov 17 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 8 | Dec 13 | Dec 17 | Dec 23 |
Freeze probabilities 1991–2020 at Laporte, 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 46360 →Compare Michigan City with another place →
Weather by month in Michigan City
July is the warmest month at Laporte, IN, averaging 82°F by day and 64°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 16% of years.
Warmth for growing adds up to 3,052 growing degree days a year (base 50°F), fewer than at 83% of the 125 Indiana stations. 34% of them (1,033) have built up by the end of June, and July adds the most, 715. Precipitation totals 42.5 inches a year, most in June (4.4") 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 | 31 | 17 | 3.0 | 100% | 28 | 0 |
| Feb | 35 | 20 | 2.5 | 100% | 25 | 2 |
| Mar | 46 | 29 | 2.7 | 100% | 21 | 23 |
| Apr | 59 | 39 | 3.8 | 96% | 5 | 103 |
| May | 70 | 50 | 4.3 | 16% | <1 | 325 |
| Jun | 79 | 60 | 4.4 | 0% | 0 | 579 |
| Jul | 82 | 64 | 4.0 | 0% | 0 | 715 |
| Aug | 80 | 63 | 4.2 | 0% | 0 | 668 |
| Sep | 74 | 55 | 3.4 | 0% | 0 | 446 |
| Oct | 62 | 44 | 4.1 | 65% | 1 | 162 |
| Nov | 48 | 33 | 3.2 | 99% | 13 | 26 |
| Dec | 36 | 24 | 2.9 | 100% | 25 | 3 |
Monthly normals 1991–2020 at Laporte, IN (809 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, Indiana Dunes Nl, IN, 12 miles southwest of Michigan City, has a last frost 3 days later (April 22), the same first-frost date, a season 3 days shorter.
When it snows in Michigan City, Indiana
The first measurable snow (0.1 inch or more) in Michigan City usually arrives around November 17, and the last of the season around April 4. Those are the middle dates across the winters of 1991–2020 at Laporte, IN, 10.2 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 15 days after the last snow.
Planting calendar for 46360
| When | What to do |
|---|---|
| February 8 – February 22 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 22 – March 8 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 22 – April 5 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 19 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 4 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 13 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 27 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 46360 is 10 miles from Laporte, IN, which stands at 809 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 46350 (La Porte). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46360 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.